Accelerative Test of Rail Welds at TTC, U.S.A.


Katsuyoshi UEYAMA

Chief Engineer, Rail Welding Group,
Track Technology Development Department

Mitsumasa TATSUMI

Engineer, Rail Welding Group,
Track Technology Development Department

Makoto ISHIDA

Manager, Track Dynamics Laboratory


   Railway Technical Research Institute (RTRI) signed a contract with 
Association of American Railroads (AAR) in 1995. In the contract, AAR 
agreed to provide the facilities and resources necessary to conduct or 
support the testing on RTRI-provided equipment and/or material at the 
Transportation Technology Center (TTC), Pueblo, Colorado.
   As a first test, the accelerative test of rail gas pressure welds was 
started at the Facility for Accelerated Service Testing (FAST) High 
Tonnage Loop (HTL) in March 1996 (Figure 1). The objective of this test 
is to obtain some data on welded rail end batter (WREB) of Japanese 
Industrial Standard (JIS) 60kg standard carbon rail in track, thereby to 
establish the maintenance and control methods for longitudinal rail profile 
on running surface. The WREB has an effect on the fatigue strength of rail 
weld, and causes running noise and track vibration during train operation.
   The two 25 meter long JIS 60kg rails containing three gas pressure welds on 
each rail, which were executed under various welding and postweld heat treatment 
conditions, were installed in section 5 of FAST HTL (Figure 2); these weld rails 
were joined with 136lb head-hardened rails by compromising alumino-thermic welds 
(Figure 3) and located on tangent track on both sides (Figure 4). At the 
present HTL, train operation is bi-directional under 39-ton heavy axle loads, 
and the gross tonnage passed is about one million gross tons (MGT) per day.
   In this test, longitudinal rail profile and hardness on running surface at 
each weld as the static data, and vertical force, bending stress and vibration 
acceleration at two selected welds as the dynamic data are measured at 0, 10, 
25, 50, 75 and 100 MGT. The test plan is set for about one year.