Q Bank for Civil Engineer LDCE Exam- Write Short Notes on (24)

Q No. 12: Write short notes on any five of the following: 

(a) R.A.W. 

(b) T.M.S. 

(c) Works needing CRS sanction 

(d) Thermit Welding & its quality control 

(e) TGI & OMS (f) GMF Scheme 

(g) Buckling of Track, cause & Prevention

(a) R. A. W. (Railway Affecting Works):– Are those, the construction, defective design of which may cause serious damages/breaches or flooding of railway line or bridges. Such as irrigation and water supply tanks or reservoirs, canals in embankment and river bunds, road embankment with in adequate water way for drainage situated up-stream or downstream of the railway lines and others works or operations which might alter the natural course flood flow or cause an increasing in the volume of such flow near the railway track are called rail affecting works. A separate register is to be maintained to note down all such work. Joint inspection of all RAW should be done with state authorities every year to ensure safety of this installation.

(b) TMS(Track Management System) :- TMS is a computer software which integrates various track component data, inspection data and work report data to provide useful information for taking better decisions. Concept of need based maintenance can be introduced for maintenance of track. The Indian railway introduces the web bases system to enable railway officials to check and monitor the lowest level inspections/condition of track progress of track renewal and other works. On a one click of computer screen. By this system the paper less working introduce by which nos. of inspection register and other paper record has been eliminated. Monitoring and condition of railway track at the root level increased.

(c) Works needing CRS Sanction: - CRS sanction required for the execution of any work on the open line which will affect the running of trains carrying passengers and temporary arrangements necessary carrying out it. Such as:- 

 i. Addition, Extension or alteration to running lines. ii. Alteration to Points & Xing in running line. 

iii. New Signaling and inter locking installation or alteration to existing installation. 

iv. New station temporary or permanent. 

v. Heavy regarding of running line involving lowering/raising of track in excess of 500 mm. 

vi. New Bridges, Addition or replacement of existing girders including provision of temporary girders. 

vii. Provision of new L-Xings, shifting of L-Xing, Demanding and down grading, manning of unmanned L-Xing, Upgrading of L-Xings, Closing down of L-Xings. 

viii. Permanent Diversion.

(d) Thermit Welding & its quality control: - A fish plated joint has been a necessary evil in the railway track right from beginning of railway. To overcome the various problems posed by the fish plated joints and reduced the maintenance cost the need for welding of rail ends was felt. Joining of two rails end by the application of heat is called welding. Among the various tetchiness of welding the AT welding is used now days for scattered and spot welding.

Quality control:- The quality of an AT welding could be ensure by adopting the following simple precautions. 

i. The rail ends must be cleaned and straight. 

ii. The gap should be uniformed and within limit. 

iii. All the equipment used for AT welding should be complete and in order. 

iv. Only prefabricated moulds of sound condition should be used welding portion and looting sent should not be of expiry date material. Pressure of oxygen and LPG should be as per specification adequate heating time should be given to heat up the rail ends. 

v. Ensure uniform heating of rail ends. 

vi. Welding Portion should be dry and free from any moisture content. 

vii. Corrected size of thimble should be used. 

viii. Specified mould waiting time should be achieved before trimming the weld joints. 

ix. Small track machine should be used for trimming and grinding. 

x. Chisel cutting should be avoided. 

xi. After finishing tolerances must be ensured of welding joints. 

xii. No traffic should be allowed over newly welded joint within 30 minutes of the welding.

(e) TGI and OMS:- It is utmost important to ensure passenger comfort and safety of track. In order to improve longevity of assets. This can be achieved by frequent inspection, detection of irregularities and their quick elimination, various method of inspection has been adopted by P.Way engineers.

i. By manual inspection. 

ii. By track recording cars. a. OMS-2000 :- To ensure the comfort of passengers the micro processor based system adopted to record the vertical and lateral acceleration due to gravity. The results obtain digitally in the form of peaks. b. The criteria of condition of track bases on peaks per km. (PPKM)

i. Outstanding:- Upto 0.25

ii. Very Good :- >0.25 to 1.0 

iii. Good :- >1 to 2.00 

iv. Below Avg. :- More than 2

TGI:- Is the method to assess the conditions of track parameters or obtained by standard deviation based composite track index which is work out for block of 200mtr track this composite index is based on the individual indices of unevenness, twist, gauge and alignment measured for a block of 200mtr length of track. TGI is defined as under 

TGI = 2UI+TI+6AI+GI 10 

UI= Unevenness Index 

TI= Twist Index 

AI= Alignment Index 

GI= Gauge Index

Based on TGI value classification of track is as under:- 

i. Outstanding:- 80 and above. 

ii. Very good:- 50 to 79 

iii. Good:- 36 to 49 

iv. Below avg.:- Below 36

(f) GMF(Grow More Food) Scheme:- A lot of railway land remain unused for the year and no outcome has been receive from the land. This railway land suffered temporary and permanent encroachment from the outsiders, a lot of revenue loss experienced. To secure the railway land from encroachment and to provide food grains to the poor railway employees on a small rent railway introduced the grow more food scheme for the railway employees. By this scheme railway land become secure from the outsider’s encroachment as well as railway becomes neat and clean and beautiful which improve the image of railway. Earning also increased by giving surplus land to employees.

(g) Buckling of track, Cause and prevention.-

1. Buckling of Track: - When the compressive stresses become higher than the resistance (Lateral or longitudinal or both) offered by the track structure then alignment of track (vertically or laterally or both) distorted, this phenomena is called the buckling of track. 

2. Cause:- Any act which reduces the resistance offered by the track such as:- 

 i. Weakening or removal connections between rail and sleepers such as missing or in effectiveness of rail to sleepers fitting. 

ii. Reduction of ballast resistance such as inadequate ballast cushion (which provides 70% track resistance to thermal forces) are by loose packing under sleepers 

iii. Lose/disturbed ballast profile. 

iv. Uncompacted Ballast profile.

Prevention :-

i. To ensure complete and effective rail to sleeper fitting and fastening. 

ii. Full and compact ballast cushion and profile. No maintenance or renewal activities should be done beyond the prescribed temperature