Development of Diamond

8/9/2019 Development of Diamond

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DESIGN, DEVELOPMENT & LAYING

OF INNOVATIVE NON- STANDARD SPECIAL

DIAMOND CROSSING

ON CENTRAL RAILWAY.

PRESENTED BY:

Suresh Rawat , XEN , KTT

Atul Deshpande , ADEN , BSL

(Integrated Course Number 613 )

SYNOPSIS In any yard, or elsewhere, where ever there is a need for connections from one

line to another, either cross over are needed or a need for a Diamond Crossing,

which can be either a standard Single Slip / Double Slip or a Special Diamond.

In old laid yards, it is very common to encounter Special

Diamond in which the angle of crossing is far more obtuse than the standard

Diamond crossing angle. These are unique for each locations & are called Non

std. Diamonds. These type of Diamond involve totally unsupported wheel tread

and simultaneously unguarded wheel flange, over a certain length in crossing

portion.



This often results in heavy hammering action, snapping of bolts, battering of rail

ends & fracturing of rails at nose portion, for both lines, thereby imparting heavy

damage to the, now difficult to procure/ banned, wooden sleepers. This also

affected the effectiveness of packing, thus affecting track parameters.

As a result of this necessary evil, speed restriction of 10 –15 KMPH are

invariable been imposed. Considering all above factors , it necessissiates time

loss for mail express train etc. It also involved frequent replacements of fittings

and sleepers etc.. Cases of derailments on these, in case of over speeding , also

cant be ruled out.

In order to arrest these limitations, a new innovative diamond crossing

has been developed under the guidance of Shri. S.K. Jain, PCE, C.Rly., where the

discontinuity on the main line track is completely eliminated permitting

unrestricted speed, saving the vital time loss.

The concept of flange supported travel on one line with speed restriction

& the other running over with unrestricted speed, is put to trial in field for the

1 st

time on Indian Railways.

NECESSITY

It is on open secret that maintaining existing special diamond which are unique

for each location, necessitating fabrication , take bulk of maintenance attention

and material input of a PWI .



It has been observed that the existing special diamonds on Bhusawal & Nagpur

division (as a case study) had following maintenance inputs:-

Existing Diamond Crossing with fittings

i) Due to heavy hammering action, owing to on supported wheel tread

movement, snapping / shearing of bolts was very frequent. On an average

15 to 20 bolts were snapping every month, and that too requiring

replacements urgently.

ii) Warranting replacement of battered & cracked rails at nose almost every

alternate month.

iii) Breaking of angular fish plates on an average, 2 to 3 fish plates in a month .

iv) Heavy hammering action necessitating frequent packing ,say every 5th

day.

v) Dearth of wooden sleepers , small rail length of 1.4 m length added to the

woes .

vi) Over a period of time of years, the crossing angle of the track varied due to

various & innumerable time the angular fish plates fabricated by the Black smiths,

resulting in slowly increasing the kinks in the assembly.



The introduction of the concept of flange supported travel on one line

& running over on the other, which takes care of all the above aspects.

Rather the exemplified advantage is of increased unrestricted speed potential

on Main line.

The solution of sacrificing of chord line altogether or modifying with

crossovers are difficult & costly propositions & the space available in yard may

not make it possible also.

CONCEPT In order to achieve unrestricted speed on main line, the following objectives has

to be there:-

i) Continuity of rail table & gauge face for Main Line.

ii) Uniformity of track structure ie. size of sleeper, ballast profit, & sleeper

spacing.

This shall entail the chord rail fly over the main rail. To make the fly

over possible, minimum level difference required is the maximum depth of

flange & therefore the rail top of chord line has to be raised.

This shall cause another problem of bridging the gap for passage of wheel

freely travel on the main line & no obstruction could be created for a width of

wheel thickness to wheel play, which can be broken in 3 parts, ie flange way

clearance for the main line (41 mm), rail head (67mm) & clearance required for

wheel disc on the non gauge face side (35mm).

The concept of flange supported travel for the gap on non gauge face & on

the rail table shall be made, as for the 41mm flange way clearance flange support

is not possible.



Accordingly, ramp has been provided on non- gauge face side between

check rail & running rail extended upto head of the main rail line rail , to ensure

smooth transition of load from wheel tread to wheel flange & then wheel flange

negotiates the gap on the non gauge side travelling on this ramp.

Wheel flange further travels on the head of the main line rails & then the

wheel flange drops into the gap provided, the wheel tread here gets partially

supported on the running rail across gap on account of angularity.

Sketch showing the provision of Ramp for Wheel transition.

The tracking of the wheel is fairly smooth on chord line as also

observed in the field.



How ever the speed restriction of 10 KMPH on chord line is kept keeping

in view the conditions of rolling stock , as depth of flange can vary widely. The

factor of poor engineman ship also can’t be ruled out, while travel over this gap.

DEVELOPMENT

First trial of this concept was done is Manmad workshop of Central

Railway , where it was fabricated.

Based on the confidence gained, diamond on mainlines of BSL-NGP trunk

route(Double Line) with Bay line (KNW) crossing at an angle of 540

12’ 40” was

fabricated again at Manmad work shop.

This diamond @ km 447/33-35 was about 3 kms from BSL station &

existing diamond on condition basis had SR. of 15 kmph for both the lines

necessitating vital time loss.

Drawing Developed for Special Diamond



Salient features of the design were:-

S. No Description Technical Feature

1 Crossing angle 540

12’ 40”

2 Thickness of base plate 20 mm (MS)

3 Rail Section Main Line- 52 KG Rail of 7.82 m length

without notchings.

Chord line- 60 KG Rail further raised by 14

mm by welding of base plate .

(Low Hydrogen electrodes used)

4 Sleepers Wooden

5 Clearances Kept as , 41 mm at gauge face side, 67mm for

rail head for 52 kg. Rail section & 35mm

clearance on non gauge face side.

( Totaling to 143mm.)

6 Check Rails 52 KG raised by 25mm for chord line, to take

are of are angularity of Axles.

7 Fittings Normal Points and Crossing Rail screws etc.

8 Additional Strengthening

Measures

Stiffeners for bottom plate provided below each

jumping parts so that rigidity of assembly is not

reduced



LAYING OF DIAMOND AT BHUSAWAL

Briefs of the Laying are:

1) Survey of the actual intersecting angle of track crossings with the Theodolite which was

540

12’ 40”.

2) Then the layout location was studied and the references marked at site.

3) The fabricated Diamond crossing was brought from Manmad workshop at Bhusawal.

4) The Existing Diamond crossing was dismantled manually.

5) Prefabricated and assembled Diamond crossing was laid on 5th of May 2005 in 2.5 hrs. of

block.

6) Necessary Ballasting, aligning and packing done and 1st

train was passed with 10KMPH.

Special Diamond Laid in Bhusawal



7) The breakup of Activities are as under:

S. No. Activity Block period Remarks

1. (Preblock) Removal of

ballast,loosening of

fastenings etc.

-

2 ( During Block

period)

Dismantling of track 40 Min.

3 Preparation of Bed 25 Min.

4 Slewing and laying of

special diamond

assembly

60 Min.

5 Ballasting,Aligning

and Packing.

25 Min.

6 Track fit given

Total 2 Hrs. 30 Min.

About 55 Labours

required for the

Execution of work.

* 24 hrs. Watchman was posted at the site thereafter.

PRECAUTION ADVISED AFTER LAYING

(i) Daily tightening of bolts by keyman & look out for cracks, if any

(ii) Wear on main line , condition of head on chord line & gap measured twice a week .

(iii) Packing of chord line, to be attended twice a week.(iv) Spare set was made available at site.

(v) Speed on this diamond was relaxed to 75 kmph after it was laid on 23.05.2005 &

24.05.2005 .



Based on the Experience gained after the laying of Bhusawal Diamond following Improvements

were done in laying of diamond on Nagpur division.

(i) Concrete SEJ sleepers used for this unique design in place of Wooden sleepers

(ii) Check rails of angles , used for mainline

(iii) No holes made in 52kg. Main line to facilitate very easy removal/ renewals within least

block period.

(iv) All 4 Diamonds 9, 10 , 11, 12 crossing Mumbai-Howrah Main trunk Routes and Two

Chord lines from Itarsi to Goods Yard , laid at the same time

One of the Diamonds laid in Nagpur

(v) Arrangement made at site for welding of few inserts, for ERC at some locations, which

was not done in Manmad Workshop.

A block of 6 hrs. taken for all diamonds. Two T-28 machine were used to lay the

Diamond assembly as it was a heavy assemble weighing around 45 Tones. 150 Labour

was involved.





No problem has been noticed till date with respect to the volume of traffic plying on this vital

East-west Route ‘A’ Rail route . Also no fracture has been reported till date.

These Diamonds have been Inspected by many Higher officers of Indian Railways, CRS, Central

Circle and also, inspected by the team of Ex. Director , RDSO , Lucknow.

CONCLUSION

It has been observed that the above laid special diamond crossing has been in use since last 1

year and is working safely under the passage of heavy traffic with meager maintenance inputs.

The initial and maintenance cost are also very less as its design involves simple fabricating

materials and Rails.

The procedure and the time required for replacements of Rails and components is simple and

can be replaced within very short block period.

ACKNOWLEDGEMENT

We would like to express our gratitude to Mr.S.K Jain PCE, C.Rly and Mr. Paramjeet Singh,

Dy. CE (T-1) , Mumbai in permitting us to pen down their experience and information related

to design and development and laying of this innovative design of special Diamond at Bhusawal

and Nagpur.

We also would like to express our sincere thanks to Shri.R.N Verma, SP, Track , IRICEN , Pune

for this valuable suggestions in preparation of this project report.



Above all, we would like to express our heartfelt thanks to Director, IRICEN ,Pune for having

given all of us an opportunity on expressing our point of view, on various subjects, as part of our

Course.



DESIGN, DEVELOPMENT & LAYING

OF INNOVATIVE NON- STANDARDSPECIAL DIAMOND CROSSING

ON CENTRAL RAILWAY.

PRESENTED BY:

Suresh Rawat , XEN , KTTAtul Deshpande , ADEN , BSL

(Integrated Course Number 613 )



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