LAST MONTH, Swedish State Railway’s workshops and maintenance subsidiary TGOJ ordered 70 sets of TF25SA single axle suspensions from Powell Duffryn Rail for around £2m. Derived from the company’s TF25 ’track-friendly’ bogies (RG 11.99 p739), the suspensions are to be used to uprate SJ freight vans for 160 km/h operation with 20 tonne axleloads. TGOJ is to rebuild 70 vans to improve SJ’s postal delivery times.
The contract follows trials at up to 176 km/h with prototype suspensions ordered in mid-1999. These included a completely-redesigned braking system including full wheelslip protection. The trials confirmed that the design met the requirements of both SJ and the Swedish post office, leading to the contract, which includes an option for a further 50 sets.
TGOJ has been experimenting with new-generation single-axle suspensions for several years, and recently introduced a range of high-capacity freight wagons carried on Unitruck II single-axle suspensions supplied by ABC-NACO. These wagons are based around a US-style centre sill to maximise flexibility and minimise tare weight, and the Unitruck II suspension gives a soft dual-rate suspension to cradle heavy loads and apply frictional damping to limit dynamic vertical shocks.
Reader Enquiry Numbers TGOJ, Sweden 139Powell Duffryn Rail, Great Britain 140 ABC-NACO, USA 141