QUESTION WITH ANSWER - AEN GROUP ‘B’ EXAM 2012

 CENTRAL RAILWAY

ENGINEERING DEPARTMENT

Written Examination

LIMITED DEPARTMENTAL COMPETETIVE EXAMINATION ( LDCE )

For AEN ( 30% Group ‘B’ )

Date  :  02 – 06 – 2012                                Paper - I                            Maximum Marks :    150

PART – I – General Knowledge and Hindi Policy

Attempt any five questions In Part I all Questions Carry equal marts.   

Q. 1. – Name five production units of Indian railways & their location.   2 X 5 = 10

Ans.- Five production units of Indian railways –

1. Diesel Locomotive Works ( DLW ) – Varanasi
2. Chittaranjan Locomotives Works ( CLW ) – Chittaranjan.
3. Integral Coach factory ( ICF ) – Perambur.
4. Rail Coach Factory ( RCF ) – Kapurthala
5. Diesal Component Works ( DCW ) – Patiala.

Q. 2. State the function, purpose or relevance of any four of the following in 2 – 3 lines each.

         ( a ) P.I.L.   ( b ) W.H.O.   ( c ) I.S.R.O.     ( d ) B.S.F.    ( e ) R.L.D.A.           2.5 x 4 = 10

Ans.-

( a ) P.I.L. - Public-interest litigation - 

Public-interest litigation is a rule of declared law by the courts of record. However, the person (or entity) filing the petition must prove to the satisfaction of the court that the petition is being filed for the public interest and not as a frivolous litigation for pecuniary gain.

( b ) W.H.O.   - World Health Organization –

WHO is the United Nations’ specialized agency for Health. It is an inter-governmental organization and works in collaboration with its member states usually through the Ministries of Health.

( c ) I.S.R.O.    - Indian Space Research Organization –

The Indian Space Research Organisation is the primary space agency of the Indian government ISRO is among the six largest space research organisations in the world. Its primary objective is to advance space technology and use its applications for national benefit.

( d ) B.S.F.  - Border Security Force - 

The Border Security Force (BSF) is a Border Guarding Force of India. Established on December 1, 1965, it is a paramillitary force charged with guarding India's land border during peace time and preventing transnational crime.

( e ) R.L.D.A.   - Rail Land Development Authority -

RLDA is a statutory Authority under the Ministry of Railways, set-up by an Amendment to the Indian Railways Act, 1989, for development of vacant railway land for commercial use for the purpose of generating revenue by non-tariff measures.

Q.3. Write short notes on any two of the following. –                                             5 x 2 = 10

        ( a ) World heritage sites  ( b ) e tendering. ( c ) BOT / Boot Schemes.

Ans.- 

( a ) World heritage sites –

In 1972, the General Conference of UNESCO adopted a resolution with overwhelming enthusiasm creating thereby a 'Convention concerning the protection of the World Cultural and Natural Heritage'. The main objectives were to define the World Heritage in both cultural and natural aspects; to enlist Sites and Monuments from the member countries which are of exceptional interest and universal value, the protection of which is the concern of all mankind; and to promote co-operation among all Nations and people to contribute for the protection of these universal treasures intact for future generations. 

India is an active member State on the World Heritage from 1977 and has been working in close co-operation with other International agencies like ICOMOS (International Council on Monuments and Sites), IUCN (International Union for the Conservation of Nature and Natural Resources) and ICCROM (International Centre for the study of Preservation and Restoration of Cultural Property). 

Darjeeling Himalayan Railway declared ‘’World heritage sites’’ by UNESCO in 1999.   

( b ) e tendering –

The e-Tendering.com is enhanced to support Microsoft Internet Explorer version 6, 7, 8 and 9. The E-Tendering System will conduct a browser checking of your machine when you log in the system to ensure that you have installed the appropriate browser for activating the E-Tendering System.

In addition, the system behavior of the Tender Submission part has some minor differences on IE8 or above version with IE7 or below version, users are reminded to go through the Supplier User Guide (For IE 8 or above) for the appropriate operation action.

This is an official website of Indian Railways for procurement of Materials. Railway users can upload their tender documents and can open tenders online. Registered Vendors can access the tender documents through this site and submit their bids online duly encrypted at client machine itself.

( c ) BOT / BOOT Schemes -

Build–operate–transfer (BOT) or build–own–operate–transfer (BOOT) is a form of project financing, wherein a private entity receives a concession from the private or public sector to finance, design, construct, and operate a facility stated in the concession contract. This enables the project proponent to recover its investment, operating and maintenance expenses in the project.

Due to the long-term nature of the arrangement, the fees are usually raised during the concession period. The rate of increase is often tied to a combination of internal and external variables, allowing the proponent to reach a satisfactory internal rate of return for its investment.

A BOOT structure differs from BOT in that the private entity owns the works. During the concession period the private company owns and operates the facility with the prime goal to recover the costs of investment and maintenance while trying to achieve higher margin on project. The specific characteristics of BOOT make it suitable for infrastructure projects like highways, roads mass transit, railway transport and power generation and as such they have political importance for the social welfare but are not attractive for other types of private investments. BOOT & BOT are methods which find very extensive application in countries which desire ownership transfer and operations including. Some advantages of BOOT projects are:

1.    Encourage private investment

2.    Inject new foreign capital to the country

3.    Transfer of technology and know-how

4.    Completing project within time frame and planned budget

5.    Providing additional financial source for other priority projects

6.    Releasing the burden on public budget for infrastructure development.

Q.4. Why were the following in news recently ? ( Answer any four )                        2.5 x 4 = 10

        ( I ) Yuvraj Singh                      ( ii ) Face book            ( iii ) Exchange rate of rupee.

        ( iv ) Adarsh housing society.   ( v ) King Fisher airlines.

Ans. -

( I ) Yuvraj Singh                      

Cricketer Yuvraj Singh as he is the best inspiration. The way he fought Cancer and came out as a winner is very inspirational. Nobody believed the news that a player like Yuvraj Singh could suffer from cancer. But hat's off to his spirit and hope to see him soon on the field."

( ii ) Face book –

Recently in May 2012 introducing Camera, a new mobile app that makes using Face book photos faster and easier. You can See friends’ photos all in one place.

When you launch the app, you'll see a feed of just great photos from the people you care about. You can swipe to see more of any album or tap to enlarge an individual photo.

Now you can quickly share multiple photos all at once instead of having to post one at a time. Just select the shots you want to share by tapping the check-mark on each photo and then hit post. You'll have a chance to add a caption, say where you were and tag friends before you share.

It's also easy to edit photos with new tools like the ability to crop, rotate and add filters to any picture in your camera roll.

Camera will be available for iPhone starting later today. Get a link to the app texted to your phone or just search for 'Facebook Camera' in the App Store.

( iii ) Exchange rate of rupee.

The sale of non-rupee bonds has plunged to a four-year low as corporates whipsawed by a sliding rupee and increasing spread overseas preferred to borrow from local lenders. The decline in sale of bonds, denominated in currencies that are stronger than the rupee, nullifies the Reserve Bank of India's efforts to bring in dollars through overseas borrowing to stabilise the Indian currency. The total amount raised by Indian companies through non-rupee denominated bonds, including the US dollar, Swiss franc and Chinese yuan, fell to $16 million in May from $3,146 million a year ago, according to data from Dealogic.

( iv ) Adarsh housing society

The society, originally meant to be a six-storey structure to house Kargil war heroes and war widows, was converted into a 100-metre-tall building. Retired brigadier M W Wanchu, the president of the society, argued that it was not a defence land.

According to the present market rate in the Colaba area, an average two-to three-bedroom-hall-kitchen (BHK) flat in Adarsh society could cost between Rs 6 crore and Rs 8.5 crore. However, members of the society paid Rs 60-85 lakh for each flat.

The CBI is already investigating how the prime land in Mumbai, which was marked for Kargil war widows and war veterans, was given to VIPs instead. The CBI enquiry was sought by the present Army chief to clear the names of defence service officers allegedly implicated in it.

( v ) King Fisher airlines –

During late February 2012, Kingfisher Airlines started to sink into a fresh crisis. Several flights were cancelled and aircraft were grounded. The cash-strapped airline claimed that the disruptions will continue for four days due to unexpected events including bird strikes which rendered aircraft out of service. The airline shut down most international short-haul operations and also temporarily closed bookings. Out of the 64 aircraft, only 22 were known to be operational by 20 February. With this, Kingfisher's market share clearly dropped to 11.3%. The cancellation of the flights was accompanied by a 13.5% drop in the stocks of the company on 20 February 2012. The CEO of the airlines, Sanjay Agarwal was summoned by the Directorate General of Civil Aviation and the Chairman CBDT to explain the disruptions of the operations.

In March 2012, the airline was suspended by the International Air Transport Association from using its inter-airline fund clearing system, the suspension means the airline will have to deal directly with other airlines when sharing revenue on services.

The Income Tax authorities in India have frozen accounts due to Income Tax deducted from Employees Salaries and not deposited with the Government since March 2009, apart from non payment of Service Tax.

Due to the ongoing financial crisis, an Airbus A330-200 aircraft was impounded at London Heathrow Airport in the United Kingdom under Court Orders due to unpaid fees to aircraft leasing companies and RBS.

Q. 5. Write the designation of person heading of following units / organizations ( Any four )

        ( I ) Railway Work shop   ( ii ) R.D.S.O.   ( iii ) Division of Railway   ( iv ) R.R.B  

        ( v ) R.P.F. department at zonal level.                                                     2.5 x 4 = 10

Ans.-

( I ) Railway Work shop                          -      Chief Work shop Manager( CWM ).

( ii ) R.D.S.O.                                          -      Director General.

( iii ) Division of Railway                         -      Divisional Railway Manager ( DRM ).

( iv ) R.R.B                                              -      Chairman

( v ) R.P.F. department at zonal level.    -      Chief Security Commissioner.      

Q.6. According to Rajbhasha rules which employee is considered proficient in Hindi.        10

®úÉVɦÉɹÉÉ ÊxÉªÉ¨É Eäò +xÉÖºÉÉ®ú ʽþxnùÒ ¨Éå |É´ÉÒhÉiÉÉ |ÉÉ{iÉ Eò¨ÉÇSÉÉ®úÒ ÊEòºÉä ºÉ¨ÉZÉÉ VÉÉiÉÉ ½èþ *

=kÉ®ú - ®úÉVɦÉɹÉÉ ÊxÉªÉ¨É Eäò ÊxÉªÉ¨É 9 Eäò +xÉÖºÉÉ®ú ʽþxnùÒ ¨Éå |É´ÉÒhÉiÉÉ |ÉÉ{iÉ Eò¨ÉÇSÉÉ®úÒ =ºÉä Eò½þÉ VÉÉiÉÉ ½èþ ªÉÊnù =ºÉ Eò¨ÉÇSÉÉ®úÒ xÉä -

¨ÉèÊ]ÅõEò {É®úÒIÉÉ ªÉÉ =ºÉEäò ºÉ¨ÉiÉÖ±ªÉ ªÉÉ =ºÉºÉä =SSÉkÉ®ú EòÉä<Ç {É®úÒIÉÉ Ê½þxnùÒ ¨ÉÉvªÉ¨É ¨Éå =kÉÒhÉÇ EòÒ ½èþ *

                                               ªÉÉ

ªÉÊnù ´É½þ ÊxɪɨÉÉå Eäò ={ÉɤÉvnù |ÉÉ°ü{É ¨Éå PÉÉä¹ÉhÉÉ Eò®úiÉÉ ½èþ ÊEò =ºÉä ʽþxnùÒ ¨Éå |É´ÉÒhÉiÉÉ |ÉÉ{iÉ ½èþ iÉÉä =ºÉEäò ¤ÉÉ®äú ¨Éå ªÉ½þ ºÉ¨ÉZÉÉ VÉɪÉäMÉÉ ÊEò =ºÉxÉä ʽþxnùÒ |É´ÉÒhÉiÉÉ |ÉÉ{iÉ Eò®ú±ÉÒ ½èþ *

iÉlÉÉ ®úÉVɦÉɹÉÉ ÊxÉªÉ¨É Eäò ÊxÉªÉ¨É 10 ( 1 ) Eäò +xÉÖºÉÉ®ú ʽþxnùÒ ¨Éå EòɪÉÇ ºÉÉvÉEò YÉÉxÉ |ÉÉ{iÉ Eò¨ÉÇSÉÉ®úÒ =ºÉä Eò½þÉ VÉÉiÉÉ ½èþ ªÉÊnù =ºÉ Eò¨ÉÇSÉÉ®úÒ xÉä -

¨ÉèÊ]ÅõEò ªÉÉ =ºÉEäò ºÉ¨ÉiÉÖ±ªÉ ªÉÉ =ºÉºÉä =SSÉkÉ®ú EòÉä<Ç {É®úÒIÉÉ Ê½þxnùÒ Ê´É¹ÉªÉ Eäò ºÉÉlÉ =kÉÒhÉÇ EòÒ ½èþ ªÉÉ EäòxpùÒªÉ ºÉ®úEòÉ®ú EòÒ |ÉʶÉIÉhÉ ªÉÉäVÉxÉÉ Eäò +xiÉMÉÇiÉ +ɪÉÉäÊVÉiÉ |ÉÉYÉ {É®úÒIÉÉ =kÉÒhÉÇ Eò®ú ±ÉÒ ½èþ *

                                               ªÉÉ

ªÉÊnù ´É½þ <xÉ ÊxɪɨÉÉå Eäò ={ÉɤÉvnù |ÉÉ°ü{É ¨Éå PÉÉä¹ÉhÉÉ Eò®úiÉÉ ½èþ ÊEò =ºÉxÉä BäºÉÉ YÉÉxÉ |ÉÉ{iÉ Eò®ú ʱɪÉÉ ½èþ iÉÉä ªÉ½þ ºÉ¨ÉZÉÉ VÉɪÉäMÉÉ ÊEò =ºÉxÉä ʽþxnùÒ EòÉ EòɪÉÇ ºÉÉvÉEò YÉÉxÉ |ÉÉ{iÉ Eò®ú ʱɪÉÉ ½èþ * 

PART – II – Civil Engineering ( General )

Answer any five questions in Part II. All questions carry equal marks.

Q. 1 ( a ) What do you understand by closing error ? What precautions are required to minimize it?                                                                                                                       8

        ( b ) The height of a Chimeney across the river is to be determined. You have only theodolite & measuring tape. You can not cross river to reach near the chimeney. Describe procedure & required calculations using trigonometery. Assume plain ground on both sides.                                                                                        12

Ans.-

( a ) Closing error –

In traverse surveying the direction of survey lines are fixed by angular measurements and not by forming a network of triangulations. A traverse survey is one in which the framework consists of a series of connected lines, the lengths and directions of which are measured with a chain or a tap, and with an angular instrument respectively.

A closed traverse is said to be closed when a complete circuit is made, when it returns to the starting point forming a closed polygon.

The closing error also termed as the error of closure is the actual distance by which the traverse fails to close.

Following precautions are required to minimize it -                                                                                                                     

i.      If the closing error is large it indicates that an error has been made in chaining and the lines require to be remeasured.

ii.     If it is small it may be eliminated and the traverse is made to close by slightly modified the shape of the polygon.

iii.    The closing error is distributed among the stations of the traverse by shifting each station by an amount proportional to the total distance of that station from the starting point of the traverse and parallel to the direction of the closing error.

( b )

Let Height of Chiminey AB = x , and width of River AC = y

Take Theodolite at point C and Take reading of angle of Chiminey top i.e. Point B = β

Now Theodolite to be shifted from C to Point D at the distance about 100 m. and Take reading of angle of Chiminey top i.e. Point B = α

In the Figure –

Δ ABC -                x

              tan β = ------,           x = y tan β,

                             y

ΔABD –                     x

             tan α  = -------------- ,  x = ( y + 100 ) tan α

                           ( y + 100 )

y tan β = ( y + 100 ) tan α = y tan α + 100 tan α,

y tan β - y tan α = 100 tan α,        y ( tan β - tan α ) = 100 tan α,

          100 tan α

Y = --------------------

       ( tan β - tan α )

                                                                100 tan α

Height of Chiminey AB = x = y tan β =  ------------------ x tan β

                                                              ( tan β - tan α )

                            

Q. 2  - What do you understand by the following ? ( Any Five )                  4 x 5 = 20

           ( I ) Plasticity index.    ( ii ) Elastomeric bearings      ( iii ) Yield stress.     

           ( iv ) Uniformity Coefficient.    ( v ) Triangulation Method.     ( vi ) Floculation.     

           ( vii ) Catchment area.

Ans.-  ( I ) Plasticity index –

It indicates the Plastic range of the soil and is the numerical difference between liquid limit and Plastic limit.     \ PI = LL – PL.

This index depends on the Plasticity of soil –

Plasticity Index	Degree of Plasticity	Plasticity Index	Degree of Plasticity
0 - 5	Non Plastic.	15 – 40	Plastic.
5 – 15	Moderately Plastic.	Above 40	Highly Plastic.

( ii ) Elastomeric bearings –

Made of natural or synthetic rubber of shore hardness of approximately 50 to 70. They are very stiff in resisting volume change but are very flexible when subjected to shear. They are generally reinforced with steel plates in alternate layers to reduce bulging. When used with a steel or concrete girder these permit moderate longitudinal movements and small rotations at the ends. These are provided for bridges having RCC or Pre stressed girders and can take deflection a well as movement

( iii ) Yield stress-     

The stress level at which a metal or other material ceases to behave elastically. The stress divided by the strain is no longer constant. The point at which this occurs is known as the yield point.

Common metals like steel, brass, aluminum behave in a predetermined fashion when subjected to external force. When a metal rod is pulled gradually, its length increase the stress and strain graph, when drawn will appear as shown below –

It can be seen that from A to B the graph is a straight line which means that the elongation to force applied.

Beyond the point B the metal yield and elongation is much more than the force applied then at Point c there is ultimate failure. The Point B denotes yield strength and point C denotes ultimate strength.

Safe stress or Working stress or Ultimate stress is taken in our design calculations because stress up to which a structure can work safely without permanent set well within elastic limit.

( iv ) Uniformity Coefficient –

Uniformity Coefficient test should be carried out for specification of Blanket Material. The Blanket material should be well graded with Uniformity coefficient C_u = D ₆₀/D₁₀ > 4 ( preferably > 7 ).  

( v ) Triangulation Method –

Triangulation is based on the trigonometrically proposition that if one side and the three angles of application be known the remaining sides can be computed by the application of the sine rule. In this method suitable points called Triangulation Station are selected and established through out.

( vi ) Floculation -  

Floculation is a process with the sedimentation with coagulant procedure.  A coagulant is a chemical compound which when added to water forms a heavier flocculate precipitate, known as floc. The process is called Flocculation.

( vii ) Catchment area -

It is the area from which rain fall flows into a drainage line, out fall or reservoir etc. The boundary line of this basin or reservoir is called the water shed. The catchment area is the surface on which the rain water falls.  The area of land bounded by watersheds draining into a river, basin, or reservoir also called catchment basin drainage area drainage basin.

Q. 3.- ( a ) What are different types of cement in use for variety of construction work.    10

          ( b ) What common tests are conducted on cement? Name the various admixtures for use with concrete.                                                                                       10

Ans- ( a ) Different types of cements - 

( 1 ) 33 Grade Ordinary Portland Cement: IS 269-1989

This ordinary basic Portland cement is in maximum use in the country and is the most suitable cement for all masonry and general concrete works where the members are not to take very high stresses.

( 2 ) 43 Grade Ordinary Portland Cement: IS 8112-1989

( 3 ) 53 Grade Ordinary Portland Cement: IS: 12269-1987

Both above types of cements are used where high early strengths in 1 to 28 days range are required.

( 4 ) Portland Pozzolana Cement: IS: 1489-1991

The  pozzolana used in the manufacture of Portland pozzolana cement is burnt clay, shale, or fly ash. The proportion of pozzolana used varies between 10 to 25 per cent by weight of cement as stipulated by Bureau of Indian Standards. 

( 5 ) Portland (Blast Furnace) Slag Cement: IS: 455-1989

This type of cement is manufactured by intergrinding the portland cement clinker and blast furnace slag in the proportion of  blast furnace slag not exceeding 65% as per Bureau of Indian Standards. 

( 6 ) Rapid Hardening Portland cement: IS 8041-1990

This cement attains greater strengths at early ages and is hence sometimes called as high early strength cement. 

( 7 ) Hydrophobic Portland Cement: IS 8043-1991

This is a cement, which repels water, and can be transported even during rains and stored in humid conditions.

( 8 ) Low Heat Portland Cement: IS: 12600-1989

In massive structures such as concrete bridge abutments, retaining walls, etc. when concrete is poured it generates considerable heat due to chemical reaction which takes place while cement is setting and hardening,

( 9 ) Sulphate resisting Portland Cement: IS: 12330-1988

In such areas of alkali conditions, for doing works like canal lining, pipe lines, culverts etc. a cement resistant to sulphate attack of very high degree is required.

( 10 ) High Alumina Cement: IS 6452-1989

The main characteristic features of high Alumina cements are they attain high early strength, high heat of hydration and have a good resistance to chemical attack. Initial setting time for high Alumina cement is just 3 minutes when compared to 30 to 45 minutes taken by ordinary portland cement.

( 11 ) White Portland Cement: IS:8042-1989

White colour it is mainly used in interior and exterior decorative works such as external renderings of buildings, facng slabs, terrazzo tiles and floorings, ornamental concrete products, swimming pools, etc.

( b ) Common tests are conducted on cement –

Field Test –

1.  Colour of the cement should be uniform and grey.

2.  Cement should feel smooth when touched or rubbed in between fingers like flour. If hand is inserted in a bag it should feel cool. If a small quantity of cement is thrown in a bucket of water it should sink and should not float on the surface.

3.  Cement should be free from any hard lumps.

Laboratory Tests -

1.  Fineness Test – It should be done by sieve analysis / Air Permeability apparatus. Cement Particles size should be less than 90µ ( 0.09 mm )

2.  Soundness Test – The expansion of cement is measured in laboratory by Lechatelier Mould which is an indication of free lime present in cement.

3.  Setting time ( Initial & Final ) test - Tested by Vicat apparatus, Initial setting time 30 minutes and final setting time 10 hours.

4.  Compressive Strength Test – Checked by making mortar cubes in 1 : 3 by weight and testing the cubes in compressive testing machine. It should be after 3 days – 160 Kg / cm², after 7 days – 220 Kg / cm² and after 28 days – 330 Kg / cm².

5.  Consistency of standard cement paste - Tested by Vicat apparatus.

Various admixtures -

( 1 ) Chemical Admixtures - Admixtures may be any one of the following classes for use in concrete :- 

( a ) Water  reducing or plasticizing Admixtures – lingo - sulphonate or poly hydroxy compounds.

( b ) Retarding Admixtures - Starches, Cellulose products, Sugars and hydroxyl  - carboxylic acids and their salts.

( C ) Accelerating Admixtures - Calcium chloride, flouro silicates and Triethanolamine.

( d ) Water reducing and retarding Admixtures.

( e ) Water reducing and accelerating Admixtures

( f ) Permeability reducing (water proofing) Admixtures

( 2 ) Liquid admixtures :-  Admixtures introduced into the concrete as liquids generally fall into the following categories -

( a ) Air entraining Admixtures - Animal and vegetable oils and fats; natural wood resins and their sodium salts; and alkali salts of sulphated and sulphonated organic compounds.

( b ) Water reducing.

( c ) Water reducing retarders.

( d ) Retarders.

( e ) Water reducing accelerators/

( f ) Accelerators.

Q.4.- Write short notes on any five –                                                                  4 x 5 = 20

         ( I ) Plate load test.    ( ii ) Back washing of filters.    ( iii ) Void ratio.    ( iv ) Total station.   

         ( v ) Self cleaning velocity.    ( vi ) California.

Ans. – ( I ) Plate loading test –

In general iron plates either 60 cm squares or 75 cm dia  and 16 mm thick are used, size of plate should not be less then 1/5^th of the width of foundation trench, where the test plate is to be placed on the surface. It is preferably to remove the top 23 cm of natural soil before placing the plate. It is very important to seat the plate accurately over the area and the ground should be leveled as much as possible. The plate should be rotated over the area and any irregularities over the surface trimmed off. The plate should be in contact with the soil over all its area on coarsely grained soil over which are difficult to level accurately. The plate can be seated on the layer of fine dry sand 6 mm thick. The load can be applied to the test plate.

The following methods may be adopted –

Load the soil four times the proposed design load and read settlement every 24 hours until no settlement occurs in 24 hrs. Add 50% more load and read settlement in every 48 hrs until no settlement occurs in 48 hrs. Settlement under the test load should not show more than 20 mm or increment of settlement under test load. If the above limitations are not met, repeat the test with reduced load will be taken for the safe loading capacity of the soil. At least two tests should be carried out preferably with different size of plates.

( ii ) Back washing of filters –

Back washing is the process for cleaning of rapid sand filter is effected by reversal of flow. First air is passed at the rate of 600-900 lpm / m2 at the pressure of 0.35 kg / cm² for 5 minutes in the reverse direction. After this water is passed which removes the dirt by bubbling action. The dirty back wash water flows out by a system of drains. The quantity of back wash water is about 2% of the total filtered quantity. The turbidity of effluent water from Rapid sand filter should not exceed 1 JTU. The loss of head in a clean filter should not exceed 0.15m. The purification achieved trough Rapid sand filter is 90%.

( iii ) Void ratio –

Void ratio e of a given soil sample is the ratio of the volume of voids to the volume of soil solids in the given soil mass.

            Thus   e = v_v / v_{s  ,}    v_v  = Volume of voids.  v_s = Volume of soil solids.

( iv ) Total station -  

Total stations is an optical instrument used in modern surveying. It is a combination of an electronic theodolite, an electronic measuring device and software running on an external computer.

Total station may be used to determine angles and distances from the instrument to points to be surveyed. With the aid of trigonometry the angles distances may be used to calculate the coordinate of actual position of surveyed points or the position of instrument from known points.

The data may be downloaded from the theodolite to a computer and application software will generate a map of the surveyed area.

Measurement of distance in this instrument is accomplished with a modulated microwave or infrared carrier signal generated by a small solid state emitter within the instrument’s optical path and bounced off of the object to be measured.

The modulation pattern in the returning signal is read and interpreted by the on board computer in the total station and the speed of light lag between the outbound and return signal is translated into distance. Total station can measure distances accurate to about 0.1 milimeter or 1/ 1000 foot.

( v ) Self Cleaning velocity: -

Is the velocity which causes all salvage both floating and heavy transported easily with flow.

It is essential that all sullage drains have Self Cleaning velocity as for as possible so that there are no accumulations in the sewers and the sewage does not become septic.

Self-cleaning velocity is determined by considering the particle size and specific weight of the suspended solids in sewage. A minimum velocity of 0.8 mps at design peak flow in the sewers is recommended subject to a minimum velocity of 0.6 mps for present peak flow.

( vi ) California  –

California bearing ratio (CBR)  is a penetration test for evaluation of the mechanical strength of road sub grades. It was developed by the California Department of Transportation.

The test is performed by measuring the pressure required to penetrate a soil sample with a plunger of standard area. The measured pressure is then divided by the pressure required to achieve an equal penetration on a standard crushed rock material. The test can be performed on laboratory-prepared samples or in the field. The CBR rating was developed for measuring the load-bearing capacity of soils used for building roads. The CBR can also be used for measuring the load-bearing capacity of unimproved airstrips or for soils under paved airstrips. The harder the surface, the higher the CBR rating. A CBR of 3 equates to tilled farmland, a CBR of 4.75 equates to turf or moist clay, while moist sand may have a CBR of 10. High quality crushed rock has a CBR of 100.

Q.5.- ( a ) In what manner prestressed concrete technology is economical and superior to RCC structure ? Explain with the help of a typical bending moment or stress diagram.     10

         ( b ) Draw a labeled flow diagram for treatment of water from source for a major station & colony.                                                                                                                        10

Ans.- ( a ) Prestressed concrete technology is economical and superior to RCC structure of the following reasons –

1. A Prestressed concrete member is a member of concrete in which internal stresses are introduced in a planned manner so that the stresses resulting from the superimposed loads are counteracted to a desired degree.
2. Concrete has a high compressive strength compared to its very low tensile strength.
3. In RCC members due to the low tensile resistance of concrete a large quantity of steel reinforcement is provided so that the entire tensile resistance is taken as offered by the reinforcement.
4. Concrete will also offer a tensile resistance along with the steel reinforcement and in this process will develop minute tensile stress.
5. Under the usual superimposed working loads the concrete present in the tension zone of a reinforced concrete member will develop cracks not being able to can from to the strains taking place in the steel.
6. A reinforced concrete member has other weaknesses too.
7. The dimensions of the member may also have to be determined from diagonal tensile stress considerations.
8. In the case of beams where large shear forces exist the beam sizes have got to be large to limit the diagonal tensile stresses under certain limits.
9. In the concrete member is also found to develop cracks even the absence of loads due to the shrinkage of concrete in the hardening stage.
10. Prestressed concrete member are thinner in section & therefore not heavy.

In a Prestressed concrete member all the above defects and weaknesses are made up due to under example –

A simply supported prestressed by a tendon provided through its centroidal longitudinal axis. Let the beam be subjected to an external load system. Let P be the prestressing force supplied by the tendon. Due to this prestressing force the compressive stress induced in concrete f_a = P / A where A is the sectional area of the member. If due to the dead load and external loads. The bending moment at a section is M than the extreme at the section due bending moment alone.

F_b = ± M / Z Where Z is the section modulus of the beam section.

                 

F = f_a ± f_b = P / A ± M / Z

Stress at the extreme top edge = P / A + M / Z

Stress at the extreme Bottom edge = P / A - M / Z

The amount of prestressing force we can reduce the tension at bottom or eliminate entire tension or introduce compression throughout the section of a beam so that it can resist considerably greater bending moment than ordinary reinforced concrete beam.

( b ) Flow diagram for treatment of water –

Screening  - For removing of large size of particles with the help of Screen. Screens are used at surface water intakes to prevent the entrance of leaves, twigs etc. The opening of screens is generally 6mm

Areation     - For removing objectionable dissolved gases and oxidising other soluble compounds.

Sedimentation  - The removal of suspended particles may be effected by sedimentation in a basin. As the water enters this basin, the flow velocity gets reduced. Due to gravitational pull, the suspended particles move towards bottom of this basin. The floor of the basin is given a slope towards the far end. The basin is designed in such a manner that a particle entering at the inlet and suspended particles settle by action of gravity & force vertically and gets trapped inside before reaching the outlet zone.

There are two process with the sedimentation procedure -

Coagulation – The addition of coagulant before sedimentation. The process is called coagulation.

Flocculation - A coagulant is a chemical compound which when added to water forms a heavier flocculate precipitate, known as floc. The process is called Flocculation.

Filtration  - Filtration consists of passing the water through a thick layer of sand which acts as a strainer. The water coming after sedimentation is passed through filter media. There are two common types of filtration beds, namely slow sand filter and rapid sand filter. For very small works pressure filters may also be used. One more filter design of Sujala filter module by the central Railway.

Disinfection of water : This is the process of destroying organic matter and bacteria from the water before it is consumed. Among the most common agents of disinfection are chlorine, ozone and ultraviolet. Chlorination is the generally adopted.

Chlorination –

The process of applying small quantities of chlorine to water is called chlorination.

Chlorine can be applied may be any one of the following –

1. Bleaching powder 2. Hypochlorities   3. Chloramines            4. Chlorine dioxide    5. Liquid chlorine 6. Chlorine gas.  7. Sodium Hypochlorid.

Chlorination should be done generally using chlorine Gas or other similar methods by Engineering department. At other places chlorination has to be done by mixing good quality bleaching powder solution at a particular rate with raw water in the pumping main at the pump house it self or at the high level storage Tanks by the IOW.

Q.6.- ( a ) Explain the procedure for estimating design discharge for bridges. What do you understand by economic span.                                                                                  10

           ( b ) What steps are involved in designing a retaining wall? Also indicate various forces to be considered with help of a diagram.                                                                       10

Ans. – ( a ) Procedure for estimating design discharge for bridges  -

Where stream flow records ( yearly peak discharges ) are available for the desired recurrence interval or more, the design discharge shall be the computed flood for the desired recurrence interval.

Where such records exist for less than the desired recurrence interval, but are of sufficient length to permit reliable statistical analysis, the design discharge may be computed statistically for the desired recurrence interval.

Where records of floods are not of sufficient length to permit reliable statistical analysis but where rainfall pattern and intensity records are available for sufficient length of time and where it is possible to carry out at least limited observations of rainfall and discharge, unit hydrographs based on such observations may be developed and design discharge of the desired recurrence interval computed by applying appropriate design storm. 

Where such observations, as mentioned above, are not possible, a synthetic unit hydrograph may be developed for medium size catchment ( i.e. area 25 sq km or more but less than 2500 sq km ) by utilising established relationships as mentioned in Flood Estimation

Report for respective hydro-meteorological sub- zone. Subsequently, design discharge may be computed in the manner, as mentioned above.

For small size catchment  ( less than 25 sq.km ), design discharge may be estimated using the techniques described in  RDSO report no.RBF-16,

Where feasible, gauging of the stream may be done to establish the stage – discharge relationships and the discharge at known HFL determined.  Otherwise, the discharge may be estimated by slope area method after obtaining flood slope by field observations.

Economic Span of a Bridge.     –

The span for which the total cost of bridge will be minimum is known as the economic span.

The ratio of Cost of super structure and Cost of Sub structure = 1

Economical Span = Ö P / a  , 

Where -    a = p / l² ,  p = Cost of pier ( Super structure ) ,   l = Span, 

                 P = Cost of Pier ( Sub Structure ) ,     a = Constant of variation.

( b ) Steps involved in designing a retaining wall –

1. Design constants – For M15 and Fe 415, σ_cbc = 5 N / mm²,  m = 18.66, σ_st = 230 N / mm², 

x = 0.29d, z = 0.90d, M_r = 0.65 bd², p_t = 0.32.

2. Trial dimensions of wall -

1. The length of the base is between 0.4 to 0.7 times the height of the wall.
2. Toe to base ratio is 1 : 4.
3. The thickness of base slab shall be more than thickness of the stem at the bottom.
4. The minimum thickness of the stem shall be 200 mm.

3. Earth pressure on wall –

From Rankine’s theory of earth pressure –

                      WH² ( 1 – sin F )

               P = -------(--------------)

                         2   ( 1 + sin F )

Where – P = total pressure on wall acting at H / 3 from the base.   H = total height in meters.

               W = weight of density of earth in kN / m³ . F = angle of repose of earth.

4. Bending moment & Thickness of stem -

Bending moment     M = P x H / 3

Thickness of stem -  M = M_r = 0.65 bd²

5. Steel -                M

                    A_st  = ------

                             σ_st z

6. Distribution Steel – 0.12 % of A_g Where A_g = Cross section area of stem at center.

7. Stability of retaining Wall -

Factor of safety for overturning –             Moment due to load of wall

                                                                -------------------------------------  ≥ 1.5

                                                                      Moment due to force P

Factor of safety for Sliding -                     Total load of wall x µ

                                                                -----------------------------    ≥ 1.5

                                                                           Force P 

Where -  µ = coefficient of friction between base and the ground below.

8. Check for shear -                    V

                                         _v  =  -------

                                                     bd

For concrete M15 and p_t = 0.31 and _c = 0.22 N /mm²

If _c > _v  no shear reinforcement is required.

9. Development length -                F σ_s

                                                                     L_d =  ------------

                                                        4 _bd   

      

Q.7.- ( a ) Draw the bending moment diagram for the following beam indicating values at critical locations.                                                                                                                   12

          ( b ) Draw shear force diagram for the following beam showing values.                          8

Ans.-  ( A ) Taking moments about A

            RB x 6 = ( 4 x 6 x 3 ) + ( 8 x 4 ) + ( 8 x 2 )  = 72 + 32 + 16 = 120

            RB = 120 / 6 = 20 T  

            And RA = ( 8 + 8 + 4 x 6  ) – 20 = 40 – 20 = 20 T.

Bending Moment Diagram

Bending Moment –

The Bending Moment Diagram is drawn in fig. And the values are tabulated hear

MA = 0 , MC =  ( 20 x 2) – ( 4 x 2 x 1 ) = 40 – 8 = 32 Tm ,

MD = ( 20 x 4 ) – ( 4 x 4 x 2 ) – ( 8 x 2 ) = 80 – 32 – 16 = 80 - 48 = 32 Tm.      MB = 0

Maximum Bending Moment –

Since RA = RB  Hence Maximum Bending Moment at Center.

MM = ( 20 x 3 ) - ( 4 x 3 x 1.5 ) – ( 8 x 1 )  = 60 – 18 – 8 = 34 Tm.

( b ) Shear force - The S. F. Diagram is shown in fig and the values are Tabulated hear –

FC = 0 T,      FB = 1 x 1.5 = 1.5 T,  and  1.5 + 1 = 2.5 T,    FA = ( 1 x 3 ) + 1  = 4 T.

****************************************

      CENTRAL RAILWAY

ENGINEERING DEPARTMENT

Written Examination

LIMITED DEPARTMENTAL COMPETETIVE EXAMINATION ( LDCE )

For AEN ( 30% Group ‘B’ )

 Date  :  03 – 06 – 2012                                Paper - II                           Maximum Marks :    150

Part I - PROFESSIONAL SUBJECT

Attempt any five questions in Part I Marks indicated with questions.

Q.1 ( a ) Describe method of classifying level crossings based on volume of rail and road traffic.

                                                                                                                                                  8

       ( b ) What are guidelines for determining length of transition curve.                                 8

       ( c ) What do you understand by interlocked level crossing.                                             4

Ans. –

( a ) Method of classifying level crossings based on volume of rail and road traffic  – The classification of level crossings should be settled in consultation with the Road authorities concerned keeping in view the class of the road, visibility conditions, the volume of the road traffic and the number of trains passing over the level crossing.

The classification of level crossings shall be as under-

(a) Special ..............: for roads.

(b) ‘A’ Class.............. : for roads.

(c) ‘B’ Class ..............: for roads.

(d) ‘C’ Class ..............: for roads

(e) ‘D’ Class for cattle crossings.

Level crossings over colliery, factory and other similar sidings where Railway traffic is light may however be dealt with according to local conditions, subject to the approval of the Commissioner of Railway Safety concerned being obtained in each case to the measures adopted for the safe working of trains over the crossing.

( b ) Guidelines for determining Length of Transition Curve -

( 1 ) The desirable length of transition ‘L’ shall be maximum of the following three values

(a) L= 0.008 Ca X Vm

(b) L= 0.008 Cd X Vm

(c) L= 0.72 Ca

Where :-  L = the length of transition in metres. Vm = maximum permissible speed in km.p.h. Cd = cant deficiency in millimetres. Ca = actual super elevation on curve in millimetres.

The formula (a) and (b) are based on rate of change of cant and of cant deficiency of 35 mm. per second. The formula ( c ) is based on the maximum cant gradient of 1 in 720 or 1.4 mm. per metre.

( 2 ) For the purpose of designing future layouts of curve, future higher speeds ( such as 160 km./ h. for Group ‘A’ routes and 130 km./ h. for Group ‘B’ routes ) may be taken into account for calculating the length of transitions.

( 3 ) In exceptional cases where room is not available for providing sufficiently long transitions in accordance with the above, the length may be reduced to a minimum of 2/3 of the desirable length as worked out on the basis of formula ( a ) and ( b ) above or 0.36 Ca ( in metres ) whichever is greater. This is based on the assumption that a rate of change of cant / cant deficiency will not exceed 55 mm. per second and the maximum cant gradient will be limited to 2.8 mm. per metre or 1 in 360. This relaxation shall apply to Broad Gauge only.

( 4 ) At locations where length of transition curve is restricted, and therefore, may be inadequate to permit the same maximum speed as calculated for the circular curve, it will be necessary to select a lower cant and / or a lower cant deficiency which will reduce the maximum speed on the circular curve but will increase the maximum speed on the transition curve. In such cases, the cant should be so selected as to permit the highest speed on the curve as a whole.

( c ) Interlocked level crossing -

Interlocked Level Crossing gate provided with telephone and gate signals -

1.    The normal position of gate generally is open to  road traffic. 

2.    The  Station Master shall advise the  Gateman  of  the passage  of train on the telephone, before permitting a train  to enter into the block section.

3.    On getting advice of a train, the Gateman shall  ensure that  the gate is closed and locked to the road traffic and  then take off Gate signals.

4.    In case the Gateman is not responding on the  telephone or in case the telephone becomes defective, the  Station  Master shall adhere to the procedure.

Q. 2 ( a ) Describe salient features of UNIMAT Machine. What design improvements have been effected in their subsequent series?                                                                            10

         ( b ) How will you compute the permissible speed over curved main line at turnouts ( Both contrary & similar flexure cases ).                                                                                10

Ans.-

( a ) Unimat Machine – 

The machine has got 16 independently tiltable tamping tools which enable the machine to work on points and crossing as well as on plain track. The machine has a weight of about 40 tones and can give an average out put of one set of points & crossing per hour. 

Out of 16 tools 4 tamping tools are normally used at a time for maintenance of point and crossings. These tools can be tilted independently of each other so that even critical areas can be tamped. 

While tamping plain track all the 16 tools are in action and in that situation the machine corresponds to a normal plain line tamping unit.

( b ) Permissible Speed over curved Main line at Turn-outs – Subject to the permissible run through speed governed by the interlocking standard, speed over the main line will be determined taking into consideration the maximum cant which can be provided on the main line and the permissible amount of cant deficiency. In the case of turn-out of similar flexure, the maximum cant that can be provided, on the main line will be the sum of equilibrium cant for the turn-out and permissible cant excess. In the case of turn-outs of contrary flexure, the maximum cant on the main line (negative super elevation on turn-out) will be the difference between the maximum permissible cant deficiency and cant determined for turn-out from the formula given in Schedule of Dimensions – C = 11860 / R, Where R = Radius of turnout in meters. The permissible negative super elevation on the turnout ( which is also the actual super elevation of the main line ) may be made as ( 75 – C ) mm. The permissible speed on the main line will be worked out by the formula - V = 0.27 √ R (Ca + Cd) ( This is on the assumption that the centre to centre distance between railheads is 1750 mm. )

Q. 3 – Write short notes on any four -                                                                             5 x 4 = 20

           ( I ) Improving quality of thermit welds.   ( ii ) Basic principles of patrol chart.   

           ( iii ) Use of rail tensors.     ( iv ) Quality control in high strength concrete.   

           ( v ) Metallising of steel girder.     ( vi ) Index plan & Section.

Ans.-

( i ) Improving quality of thermit welds - 

For improving quality of thermit welds The following precautions shall be observed :

(i) It should be ensured that the portion being used matches with type and chemistry of rail.

(ii) Rail ends should be square.

(iii) Alignment of rail ends should be perfect as checked by straight edge.

(iv) Rail ends should be properly cleaned with kerosene oil and wire brushes.

(v) Stop watch should be provided to the welding supervisor at each welding site.

(vi) Pressure in the tanks/cylinder should be properly maintained during pre-heating.

(vii) Correct gap between rail ends at head, web and foot shall be ensured.

(viii) Correct preheating time for rail ends shall be ensured.

(ix) Tightness of clips fitted with hose connections to compressor tank and burner shall be checked before commencing preheating.

(x) Nozzles of burners shall be cleaned periodically to avoid back- fire.

(xi) The compressor tank shall be kept at least 2 to 3 m away from the burner to prevent fire hazard.

(xii) The tapping shall be done within the time specified for that particular technique.

(xiii) Arrangements for giving first aid shall be available at site.

(xiv) Welders should be provided with gloves and coloured glasses.

(xv) Boiling portion shall be out tapped.

(xvi) No moist portion / torned portion bag shall be used for welding.

(xvii) Dampness in moulds can lead to porosity and early fatigue failure of welds.

(xviii) Only those contractual agencies as have clearance from the RDSO / Railway Board can execute welding work. Supply of portions must be from sources approved by RDSO / Railway Board.

(xix) Many weld failures show evidence of badly cut rail ends. The evenness and verticality of a rail cut depends solely upon the skill of the welder. With portable disc cutters, very little skill is required to produce good cut.

( ii ) Basic principles of patrol chart -

The principles governing the preparation of patrol charts shall be -

i)    Ordinary patrolling will be carried out by a single patrolman, but in regions where danger from wild animals, dacoits and other risks as in ghat sections exist, patrolling in pairs may be introduced with the approval of the Chief Engineer.

ii)   All trains carrying passengers between sunset and sunrise get the maximum protection possible.

iii)  As far as possible, each block section will be treated as a unit and the length will be divided into equal beats. The length of each patrol beat should not normally exceed 5 km. Where the block section is more than 10 km. an intermediate flag station, if any, or any other suitable point may be fixed as intermediate station, to keep the length of beat at about 5 km.

iv) The walking speed of a patrolman may be taken as 3 km. per hour.

v)  The maximum distance covered by a patrolman should not normally exceed 20 km. in a day.

vi) A period of at least & 1/2; hour rest is desirable between consecutive beats.

vii)If the frequency of train services is high, and one set of patrolmen is not able to cover all the trains in the section, a second set of patrolmen may be introduced to reduce the interval.

viii) For giving better protection to all the passenger trains, between sun-set and sun-rise it would be advantageous to plot the scheduled paths of all passenger trains and then plot the patrol movement in such a way, so as to minimise the time interval between patrolling of the beat and passage of train.

ix) Patrol charts should show all vulnerable locations where stationary watchmen are posted.

( iii ) Use of rail tensors -    

For distressing and permanent repairs Indian Railway have procured a few Rail Tensors either of hydraulic type called hydro stressors or of mechanical type called mechanical rail tensor.

A hydro stressor consists essentially of a hydraulic pump which transmits its force through connecting vans to clamps which grips the rail. In case of mechanical tensor the force is exerted mechanically by longitudinal jacks by means of this force the rail can be pushed or pulled to a desired length. In case of pushing the force should not exceed 30 tons otherwise the track is likely to buckle on that account. The rail are however normally pulled only during the distressing operations. The rail tensor is capable of distressing a rail at any time when the rail temperature is less than distressing temperature.

( v ) Metallising of steel girder -

Protective coating by metallising with sprayed aluminium to 150 micron thickness is to be provided followed by oil painting over metallised component as per schedule given below:

(i) One coat of etch primer to IS 5666 - 1970

(ii) One coat of zinc chrome primer to IS 104 - 1979

(iii) Two coats of aluminium paint to IS 2339 - 1963

In steel girder following members are to be provided with the above protection.

(1) Floor system (cross girders and rail bearers) of open web through girders in all cases

(2) Top flange plates of plate girders and under slung girders in all cases.

(3) Top bracing system of open web through spans

(4) Entire Steel girders, subjected to salt spray such as in the close vicinity of the sea and / or over creeks, as well as in industrial, suburban or coastal areas which are prone to severe

corrosive environment.

Metallising protection will be more effective and  economical if carried out in workshop during fabrication of new girders. Site metallising is not found effective as per the experience gained in the past and hence it should be planned during fabrication in workshop and metallised components handled properly during loading, unloading, while transporting from workshop to site and erection at site. Life of metallising if done in workshop with sand/grit blasting and touching up of cover aluminium oil paint whenever required will be 25 to 30 years.

( vi ) Index plan & Section-

Index plan & section prepared after final location survey of project. It should be on tracing cloth. Project sheet size is 840 x 1020 mm.

Index Plan - Show all towns, roads, canals, rivers, hills, boundaries states & districts within a distance of 10 km on either side of the line. Proposed alignment and stations should be shown in RED. Draw plan above section.

Index Section - Show formation level by RED line, indicate height of formation above mean sea level, gradients, position of important bridges, level crossing & their clause with km from fix point.

Q. 4 – ( a ) State the procedure for initial USFD testing of thermit weld. What are advantages of digital weld tester?                                                                                                 12

            ( b ) During maintenance & renewal of track, how continuity of rails in electrified section shall be maintained?                                                                                               8

Ans. –

( b ) Maintaining continuity of Rail in electrified section –

( 1 ) During maintenance or renewal of track, continuity of the rails serving electrified tracks shall invariably be maintained. For bridging gaps which may be caused during removal of fish-plates or rails, temporary metallic jumpers of approved design shall be provided as under.

( 2 ) In case of rail fracture, the two ends of the fractured rail shall be first temporarily connected by a temporary metallic jumper of approved design (as shown in the sketch below). In all cases of discontinuity of rails, the two parts of the rail shall not be touched with bare hands; Gloves of approved quality shall be used.

 

Temporary Jumpering of Rails in case of Rail Fractures

( 3 ) In the case of track renewals temporary connection shall be made.

( 4 ) In the case of defective or broken rail bond, a temporary connections shall be made.

( 5 ) Before fish-plates are loosened or removed temporary connection shall be made.

Q. 5 – ( a ) A bridge on double line electrified section is having 3 spans of PSC slabs. One of the pier has been damaged & requires rebuilding under traffic. Make out an economical rebuilding scheme and explain with a sketch list steps of execution scheme & safety precautions. Length of span to be assume.                                 15

             ( b ) Write names of different types of bearings used for supporting span of bridges. ( Both steel & Concrete girders )                                                                                 5

Ans.-

( b ) Different types of bearings- The following types of bearings are generally used in steel & Concrete girders :-

1. Sliding bearing - permitting rotation and translation.

2. Rocker and roller bearings  - permitting rotation and translation respectively. In this type of the bearing at the fixed end the girder end is fixed in apposition but rocking due to deflection under load is permitted by the curved knuckle pin. At the free end the arrangement for rocking is similar but the knuckle assembly is mounted on a set of roller to take liner expansion.

3. Elastomeric bearings - Made of natural or synthetic rubber of shore hardness of approximately 50 to 70. They are very stiff in resisting volume change but are very flexible when subjected to shear or pure uni-axial tension. They are generally reinforced with steel plates in alternate layers to reduce bulging. When used with a steel or concrete girder these permit moderate longitudinal movements and small rotations at the ends. These are provided for bridges having RCC or Pre stressed girders and can take deflection a well as movement.

4. Teflon or P.T.F.E. Bearings - The PTFE can be unfilled or filled with glass fiber or other reinforcing material. These are used either to provide rotation by sliding over cylindrical or spherical surfaces or to provide horizontal sliding movement over flat surface or a combination of both. Where there are large displacements accompanied with relatively small loadings, as in case of centrifugal loads, wind loads or seismic loads, PTFE sliding bearings are utilised.

Q. 6.- Indicate briefly technical features and advantages of any four of the following -5 x 4 =20

          ( I ) Thick web switch.         ( ii ) Septic tank.           ( iii ) R.H. Girder.  

          ( iv ) Dynamic track Stabiliser.       ( v ) Abrasive disc cutter.    ( vi ) design mode tamping.

Ans. – ( I ) Thick web switch –

The overcome some of the limitations of overriding switches RDSO has designed thick web switches based on ORE reports and foreign designs. The tongue rails are fabricated from Zu-2-49 imported asymmetrical rail section which is 116 mm high and has web thickness of 40 mm For turnout manufactured from 60 kg. rail UIS rails asymmetrical rail section ZU-1-60 is used which is 134 mm high and has web thickness of 44 mm.

The top of tounge rail is in level with stock rail, thus eliminating twist. Stock rail is prevented from lateral distortion by the projecting portion of slide chair elevated plate which holes the inner foot of stock rail. The switch is operated by double pull arrangement using GRS-5E points. The track gauge adopted is 1673 mm and switch entry angle adopted is 0⁰-20’-0’’.

Stock rail head is chamfered up to 19 mm depth. Tongue rail on stock rail side is given a slope of 1 in 4. Tounge rail foot is 40 mm higher than stock rail foot. Holes are 18 mm dia for stretcher bar. Stock rail joint and Tongue rail is joined to lead rails by forging.

( ii ) Septic tank : -    

Modern septic tank system is on a site disposal method which uses standard flushing. The septic tank acts as sedimentation cum digestion tank, Anaerobic digestion of the settled sludge occurs in its bottom zone and the supernatant liquid has to under go treatment in a soak pit / filter bed. Use of septic tank with out follow up treatment is not permitted, as the effluent from the septic tank is hazardous from the point of view of health and pollution, since it is usually not possible to provide sock pit / filter bed in built up urban areas, Septic tank system would not be appropriate in such areas.

The capacity of the septic tank should be such as to take care of the variations in the flow. A detention period of 24 to 48 hrs for tanks serving less than 50 persons and a period of 10 18 hrs for tanks serving more than 50 persons are generally adopted.

The septic tank should be constructed in 2 compartments to facilitate cleaning of one while the other is in use. A bottom slop of 5 to 10% to wards in let is recommended.

Septic tanks should be cleaned when a large quantity of sludge has collected in the bottom of the tank, The interval of cleaning should not normally exceed 12 months. No disinfectants should be used in Latrines attached to septic tanks as they kill the organism which digest sewage.

( iii ) R. H. Girder –

R.H. Girder are the box type built up duplicated girder. These are special girders ‘ Restricted Head way having over all depth 0.85 m. are used to relieve the existing bridge or its approaches. It would be observed that majority of the old culverts and bridge up to 12.2 m openings are arches and at the time of carrying in situ repairs to these arches under traffic, The severe restrictions of the clearance that could be made available for inserting these girders being merely equal to the cushion that has been provided above the crown of the arch and below the sleeper has to be 1.00 m. The length of R.H. Girder should be decided taking into consideration height of embankment , slope of exaction depth. R.H. Girder are normally available for span in the Central Railway 53’- 6’’, 44’ & 24’. Alternatively if some released girders are available these can also be used as service girders for temporary arrangements.

The following speed restriction should be imposed while using R.H.Girder.

Non stop 16 Kmph if height of sleeper crib is up to 1.52 m.

( iv ) Dynamic track Stabiliser –

During maintenance operations such as tamping, lifting, slewing, deep screening etc., the lateral resistance of track gets reduced which rebuilts gradually with passage of trains. This consolidation can also be achieved faster and more effectively by causing "controlled settlement" of track by means of a Dynamic Track Stabilizer.

Two heavy dynamic consolidating units are pressed firmly against both rails by hydraulic pressure. Fly-wheels produce a horizontal oscillation directed laterally to the track which together with a vertical load is transmitted into the track and subsequently into the ballast bed.

The dynamic effect of directional oscillation causes the sleepers to be "rubbed into'' the ballast bed and produces a "flowing movement" of the ballast which settle closer by filling of the voids. This compaction causes not only a controlled settlement of the track but also an enhanced friction between sleeper and compacted ballast bed, thus increasing lateral track resistance.

Not only the impact by the dynamic force but also a simultaneously applied static force is an important part of functioning of DTS. Hydraulic cylinders attached between the machine frame and the consolidating unit apply vertical static loads on both rails. The vertical load helps in maintaining firm contact between the consolidating units and the track for transmitting the oscillation.

DTS is equipped with a levelling system which prevents the longitudinal and cross level values from varying appreciably due to differential settlement of various segments of track. The transducers of the longitudinal level and the cross level measuring system recognise the tendencies towards formation of faults of this kind and influence the load control with their measuring signal via the automatic governor, thus counteracting the tendency of propagation of the faults.

( v ) Abrasive disc cutter –

The abrasive disc cutter used with abrasive rail cutting machine for cutting rails for various permanent way maintenance works of Indian Railways. The abrasive disc cutter is a thin circular cutting disc made of abrasive sand and bonding material.

Salient features of abrasive disc cutter  are as under –

Diameter : 400 + 5 mm & - 3 mm, Thickness : 4.0 + 0.25 mm , Nominal size : 400 x 4 x 22.23 mm. , Operating speed : 100 m per sec. approx. Performance : Minimum 7 nos. of cuts on 52 kg 90 UTS rail and 6 nos. of cuts on 60 kg 90 UTS rail at discard diameter of 260 mm.

The cutting disc shall be fixed to the spindle of the machine after ensuring that diameter of the spindle perfectly matches the bore of the cutting disc. The cutting disc shall only be used on an abrasive cutting machine originally equipped with 400 mm guards.

( vi ) Design mode tamping-

In Design Mode precise track geometry data must be known before work commences. Correct track geometry data should be input at the front tower as even small error will have a cumulative effects on the slews produced by the machine.

a) Curved Track

Versine survey of the curve is to be carried out, then slews are worked out and made available to the operator for feeding to the front tower.

b) Transition position

The correct location of transition and its location in relation to run up or down is essential. The actual sleeper at the start and end of the transition should be indicated to the operator. With this information, the length of transition can be ascertained and the tabulated values applied to the control of the machine at the front tower.

c) Straight Track

There is a possibility of a long straight track being made up of a series of smaller zig-zag straight lengths. Therefore, the theodolite should be used to establish straight line along the length of track to be corrected.

Levelling in Design Mode -

Levels of a track section are recorded by using levelling instrument. Final level along with gradients and vertical curves are decided. The required lifts are finally recorded on every alternate sleeper. Levelling is carried out by entering the lift values at the front tower.

By adopting design mode of levelling and lining desired track geometry can be achieved.

Q.7.- ( a ) Describe the preparations, quality control measures & safety precautions for working by PQRS method.                                                                                               15

          ( b ) Calculate the compensated gradient for a ruling gradient of 1 in 200 on 3⁰ curve ( Broad gauge ).                                                                                         5                                    

Ans. –

( b ) The compensation to be allowed should ordinarily be 0.04 percent per degree of curvature for Broad Gauge.

Ruling gradient = 1 in 200 = 0.5%

Degree of curve = 3⁰

Compensation for 3⁰ curve = 0.04 x 3 = 0.12%

Max. absolute gradient on curve = 0.50 – 0.12 = 0.38 %  = 1 in 100 / 0.38 = 1 in 263    

Part – II ESTABLISHMENT

Attempt any two questions in Part II Marks indicated with questions.

Q.1.- ( a ) Name the various plan heads included under demand 16. How are these works financed?                                                                                                               12

          ( b ) Explain the difference between revised & Supplementary estimate.                       6 

          ( c ) What are the main provisions of, and permissible deductions under payment of wages Act.                                                                                                              7

Ans.-

( b ) Difference between revised & Supplementary estimate –

Supplementary estimates – If it is necessary to do any additional work, after an estimate is sanctioned or if any substantial changes are required to be made Supplementary estimates are made in a similar manner as the detailed estimate. The details of items should include only the extra amount of work needed to be executed.

Revised estimates – Revision of estimates is some times necessary if there is rise in rates of materials, cost of labour, alteration in design etc. If the rise in the cost of work is likely to be more than 10% or Rs. 10,000/- a revised estimates is required to be made. Revised estimates should be prepared in the same degree of detail as the original estimates. The reasons for exceed should clearly explained.

( c ) Main provisions of payment of wages Act -

Permissible deductions : - No unauthorized deductions shall be made and following are the authorized deductions.:-

(a)  Fines.

(b)  Deduction on account of absence from duty.

(c)  Deduction for the amenities or service supplied by the employer.

(d)  Deduction for the housing accommodation provided.

(e)  Deduction for recovery of advances and adjustment of over payment of wages.

(f)  Deduction in Income Tax.

(g)  Deduction requires by the orders of court.

(h)  Subscription for PF and repayment of PF advances.

(i)   Payment for Co-operative and credit societies.

(j)   Any other deduction with written authority of employee concerned.

Q. 2. – Write short notes on any five of the following -                                                  5 x 5 = 20  

            ( I ) Suspension of a railway employee.    ( ii ) Material at site account.    

            ( iii ) Intensive classification under H.O.E.R     ( iv ) Eligibility criteria in railway tenders.

            ( v ) DCRG      ( vi ) Permanent partial disablement.     ( vii ) Operating Ratio.      

            ( viii ) Budgetary Reviews.  

Ans.-

( I ) Suspension of a railway employee –

Suspension means the suspension of official activities of a Railway employee. The suspension is not a penalty. It is an instantaneous remedy required to save any further damage being caused.

A employee may be placed under suspension where a disciplinary proceeding against him is contemplated or is pending or where in the opinion of the competent authority the employee has engaged himself in activities that can be termed to be prejudicial to  the security of the state or where a case against him in respect of any criminal offence is under investigation, inquiry or trial. 

( ii ) Material at site account  ( M.A.S. Accounts ) –

This stands for material at site account. This is a suspense head of account that is maintained to watch actual consumption of materials obtained for specific work such materials stores are requisitioned separately by the executive officer and consigned to the site of work. The monitory value of materials consumed is debited to the work concerned through works Register. The balance under this suspense represents materials on hand yet to be consumed.

( iii ) Intensive classification under H.O.E.R –

The employment of a railway servant is said to be intensive when it has been declared to be so on the ground that it is of a strenuous nature involving sustained attention or hard manual labour with little or no period of relaxation.

( iv ) Eligibility criteria in railway tenders –

The revised eligibility criteria indicated below -

Class’A’ Contractor – More than Rs. 1 crore and upto Rs. 5 crore. –

1. They should have at least a graduate Engineer having a minimum of 10 years experience plus an Engineer diploma holder having a minimum of 5 years experience.

2.They should have at least two civil engineering works costing not less than Rs. 1 crore each.

3. They should have received payments of at least Rs. 5 crore during last three years.

Class ‘B’ Contractor - More than Rs. 25 lakh and upto Rs. 1 crore.

1. They should have at least a graduate Engineer having a minimum of 5 years experience.

2.They should have at least two civil engineering works costing not less than Rs. 25 lakh each.

3. They should have received payments of at least Rs. 1 crore during last three years.

Class ‘C’ Contractor - More than Rs. 25 lakh.

1. They should have at least a diploma holder Engineer having a minimum of 3 years experience.

2.They should have at least two civil engineering works costing not less than Rs. 10 lakh each.

3. They should have received payments of at least Rs. 25 lakh during last three years.

The existing eligibility criteria may normally be taken as a general guideline for adoption in works tenders However in case of special circumstances warranting some relaxation in the eligibility criteria, CAO / C with the personal concurrence of FA & CAO / C may effect relaxation in the existing eligibility criteria prescribed and subsequent amendments thereon. This relaxation would need personal approval of CAO / C and exercise of this power shall not be re-delegated. Moreover these powers shall be exercised judiciously duly recording the special circumstances surrounding the tender in question and not in a routine manner.

( vi ) Permanent Partial disablement –

Where the disablement is of a permanent nature, such disablement as reduces his earning capacity in every employment which he was capable of undertaking at that time.

( vii ) Operating Ratio –

Operating Ratio is the ratio which the total working expenses excluding suspense of a Railway bear to its gross earning or in other words represents the percentage of working expenses in this connection include appropriation to DRF and Pension fund as well. This is used to measure the efficiency of the railway.

( viii ) Budgetary Reviews -  

Railway Administrations should review their expenditure in August to see whether any modifications are necessary in the allotments placed at their disposal.  The review in respect of each grant should be submitted, to the Railway Board in form No. F-383 so as to reach them not later than 1^st  September each year.

The administrations should review the position in as much detail as possible at the time, and if there is any new expenditure which was definitely not anticipated in the budget and which cannot be postponed without serious detriment to safety or efficiency, they should examine whether such expenditure can be met by saving in expenditure provided for in the Budget when, such savings can be foreseen or can be achieved without serious damage.  The review should show whether such examination discloses the necessity of additional grants or the possibilities of net savings, in order to enable the Board to set off savings on one railway against excesses on another and to arrive at one estimate of the net additional grant required, if any.

Q. 3. ( a ) How does Permanent negotiating Machinery ( PNM ) function at various levels on railways?                                                                                                                10                            

         ( b ) What are the guidelines for disposal of surplus railway land?                                   7

         ( c ) Explain briefly the rules governing overtime and night duty allowance.                    8

Ans. – ( a ) Permanent Negotiating Machinery (P N M)-

Two Federation of Union All Indian Railway men’s federation (AIRF) & National Federation of Indian Railway (NFIR) men have been recognized by Ministry of Railways. All the Railway units of the unions affiliated to these Federations have also been given recognition.   

With a view to maintain contact with the labour to resolve disputes & differences between labour & management & to maintain healthy industrial relations the Railway Board have set up Machinery to have a periodical dialogue with both the recognized Federations which is called PNM.

The machinery functions in three tiers as under: -

( I ) The Railway Level or Zonal Level :- 

At this level meeting between the recognized unions and administration are held at Divisional level/ workshop level and zonal level. The cases which are not decided at Divl. / workshop level are referred at zonal level. PNM meetings with each recognized union at Divl. Level is held once in two months, while at Head quarters level it is held once in a quarter. 

( ii ) The Railway Board level :- 

Matters connected with the revision of pay & allowances and other policy matters for bettering service conditions. Which are not decided at zonal level are taken up by the Federation for discussion at Board’s level in this forum. PNM meeting at Board’s level is held once in a quarter. 

( iii ) The Tribunal level :- 

Cases in which agreement is not reached between the Federation and the Railway Board and the matters are of sufficient importance are referred to an adhoc Railway Tribunal composed of representatives from the Railway Administration and Labour presided over by a neutral chairman.

( b ) Guidelines for Disposal of surplus railway land –

1. When it has been decided that a certain area of land is no longer required for Railway purposes and is eligible for disposal action should be taken.                
2. Possession should be handed over jointly by the representatives of the Railway and the State Government to the purchaser.
3. State Governments, in arranging disposal of surplus Railway land, decide to sell it by public auction, a minimum upset or reserve-price should be fixed along with such other terms, as will be beneficial to the Railway Administration with their consultation.  The auction should take place in the presence of a responsible railway representative.
4. The amount payable by the Central Government or the State Government for lands relinquished by the Railway will in all cases be their market value at the time of transfer and not the original value paid on their acquisition by the Railway.
5. In cases where Railway land is transferred to a State Government and where the capitalised value of the land revenue had been paid to the Local Government on acquisition, the amount payable by the State Government for the land should include the refund of the capitalised value.  In the case of land disposed of to private parties, the refund of the capitalised value of land revenue by the State Government will not however be necessary.
6. In all other cases, land will be disposed of at the highest offer and also if that is considered  reasonable.                   
7. In respect of relinquishment of railway land in favour of the State Government or outsiders for the approaches of ROBs / RUBs, specific approval of the Railway Board should be obtained irrespective of the value of land involved.
8. Railways should include contingency charges @ 3% in all the relinquishment estimates to cover incidental charges incurred during the process.
9. Powers of sanction - In all cases of disposals, conditions of restriction of uses agreed upon if any by both the parties may be embodied in the transfer of sale deeds.  When the estimated value exceeds Rs.5 lacs, a prior reference should be made to the Railway Board.   

( c ) Overtime and night duty allowance –

Over Time –

Under the HOER the earning of over time depends on the extra amount of work performed between the rostered hours and statutory limits or beyond the statutory limits on the basis of either daily or weekly or two weekly periods as may be prescribed for different categories.

The staff has to work over time when it is necessary due to accidents emergencies, clerical staff are not entitled for over time.

Over time is paid at one and half times of the wages per hour of duty if the employee has worked between the rostered limit and statutory limit and twice the ordinary wages per hour of duty if the employee has worked beyond the statutory limit.

Night duty allowance –

All Group ‘C’ and ‘D’ staff classified as intensive, continuous and essentially intermittent under the Hours of Employment Regulations, Group ‘C’ and ‘D’ workshop staff, and supervisory staff and sisters in charge working on regular shift duty and Group ‘C’ staff, working in confidential capacity will get weightage at the rate of 10 minutes for every hour of night duty between 22 to 06 hours and shall be paid Night duty allowance for such weightage at the rates prescribed.

**************************************

ALSO SEE - MORE RELATED FOR RAILWAY EMPLOYEE