A batch of 28 51t glw air-braked two-axle caustic soda tanks, with a carrying capacity of 36.25t and measuring 8865mm over buffers with a wheelbase of 4877 mm, were built for the wagon leasing company Tiger Rail by the Standard Wagon Co. of Heywood in 1977.
Numbered TRL 70700-27, they were fitted with Gloucester pedestal suspension units while the tank barrel, which was
