Spring failures in trains can occur due to material defects, metallurgical issues, or improper assembly. Common causes include lack of parallelism or squareness in springs, which affects how axial force is transferred. Biting, where coils contact each other, can cause breakage. Proper inspection and maintenance of parameters like stiffness, deflection, and end tapers is needed. Standards for suspension spring properties in WAP-4 and WAG-7 trains are provided. Testing data on springs removed from trains confirms dimensions and loads. Past failure rates of primary and secondary springs are reported.
Mc cormick x7.6 tier 4i (2013 ) - rpe2 - x7.660 tractor service repair manual
Anuvrat SPRING FAILURE(2015-2016)
1.
2. Spring Failure In Train
Submitted To:
Mr. R.V Singh Yadav
Submitted By :
Anuvrat Shukla
Sachin Awasthi
Bhirendra Singh
Rishabh Sharma
Shyam Dayal
Sanjay Singh
3. Types of Springs in Loco
WAG 7:-
1. Inner Spring
2. Outer Spring
WAP 4:-
1. Primary Spring
2. Secondary Spring
4. (A) Material failure(Dimensional)-
Parallelism.
Squareness.
Biting Effect.
(B) Metallurgical.
(C) Improper Critical Parameters during assembly: - It is
observed that the failures occurs due to bad maintenance
practices in respect of improper critical parameters.
Causes Of Spring Failures
5. Spring squareness is the angular difference between
the outermost limit of a spring diameter when
compared to a straightedge at a right angle to a
horizontal flat plate on which the spring is standing.
This affects how the axial force produced by the
spring can be transferred to adjacent parts in a
mechanism.
Spring Squareness
6. Spring parallelism relates to the ends of the spring
and how parallel they are to one another.
A compression spring cannot be closed and ground so
consistently that its ends will always be square (in
parallel planes at right angles to its axis).
Spring Parallelism
7. Spring should be checked properly for its Parallelism
Squareness & 75% tapered area and a gap of minimum
1.0 mm between effective coil and tapered end coil.
If there is no gap between effective coil and tapered
end coil then the biting effect will take place and the
spring will be break at that point.
Biting Effect
8. The following parameters should be ensuring
before putting the spring in the system to avoid
breakage.
(i) Free height, working height.
(ii) Stiffness and Deflection
(iii) Squareness.
(iv) Parallelism.
(v) End tapper. Where,
• Stiffness= Working load in kg/ Total
deflection=Kg/mm
• Deflection=Free Height-Working height in
mm.
9. The following precautions may be taken during
assembly of the springs in the bogie.
• Primary spring sheet of bogie frame to be checked for
any uneven surface and crackness.
• Primary spring sheet of axle box to checked for any
uneven surface and crackness.
• The squareness & surface finish of axle box crown also
to be ensured for nil gaps for proper fitment.
• Provision of polyurethane spring pad (Happy pad) to be
made at top & bottom side of the springs as
recommended by RDSO.
17. Four years details of failure / breakage of Primary & Secondary Suspension Springs,
etc are as under.
S.No. Name of Equipment 2009-10 2010-11 2011-12 2012-13
1. Primary Spring of WAP-4 21 02 POH=03 NIL
2. Secondary Spring of WAP-4 04 Nil 01 NIL
3. Primary Suspension Spring of WAG-
7(Outer/Inner)
11 07 05 NIL
4. Breakage of Bolster of WAP-4 03 06 02=POH =01
AOH=01
01
5. Breakage of Connection straps. 12 12 POH=04 NIL
18. References
• I prepared this report from the various study materials
provided by the staff officials.
• Study materials and entire technical parameters of the
subject item provided by Mr. R.V. Singh Sir.
• Entire aspects and critical parameters of the spring are
got available by Mr. R.V. Singh. Sir, Once again I would like
to thank all the staff officials for their support and
helping us in our project throughout our training period.
• We are very Thankful to Mr. SANJAY SINGH Sr.DEE/RS for
giving us an Opportunity to complete our Summer
Training at Electric Loco Shed Kanpur.
