Motion – 1999 saw a start made on forging the motion components. The first major motion components were forged for the half completed locomotive. These massive steel forgings included the three connecting rods, which transfer the power from Tornado’s three cylinders to its six 6ft 8in driving wheels. These forgings were formed from one foot square, cast steel billets weighing a total of 5 tons and were forged into shape using a 1 ton air hammer whilst at between 860 and 1200 °C by John Hesketh & Son at Bury. The forgings were forwarded in batches to be machined by Ufone Precision Engineers at Rowley Regis to be delivered to the Trust’s Darlington Locomotive Works (DLW) to be fitted to No. 60163 by July 2000. The total cost of the three sets of motion (including valve gear) was estimated to be around £130,000.
Wheelsets – The Trust made novel use of rape seed oil from Tesco’s to assemble the wheelsets. The oil, more usually found in the average kitchen, was used by the Trust’s contractor, Ian Riley of Riley & Son (Electromech) Ltd of Bury to enable Tornado’s six 6ft 8in driving wheels, four 3ft 2in front bogie wheels and two 3ft 8in Cartazzi (trailing) wheels to be pressed onto their axles.
Today, railway wheels are fitted the their axles by heating the wheels so that they expand and then shrink-fitting them to their axles. Due to the roller bearings having to be fitted to Tornado’s axles before the wheels, the Trust reverted to the traditional method of pressing on the wheels to avoid the hot wheel damaging the bearing. Tests conducted on behalf of the Trust showed that an initial interference of 0.00025 per inch of diameter, a taper on the axle of 1 in 500 and lubrication courtesy of rape seed oil from Tesco’s would facilitate the required 10 to 12 tons per inch diameter of pressing force.
David Elliott, David Champion and Dorothy Mather plus a pair of drivers!
The trial fitting of the wheels to their tyres and axles was the culmination of the most complicated logistics exercise yet undertaken by the Trust. The fitting of the 12 wheels to their axles was completed during September. The steel tyres had already been fitted to the two 3ft 8in Cartazzi (trailing) wheels by the Trust’s contractor, Ian Riley of Riley & Son (Electromech) Ltd of Bury and the tyres had been turned to their final profile, followed by the four 3ft 2in front bogie wheels. Performing a similar operation on Tornado’s six 6ft 8in driving wheels was more complicated due to their size. The demise of steam on British Railways over 30 years ago has left few workshops able to machine such large wheels – modern diesel and electric locomotive’s wheels are much smaller. Tornado’s six 6ft 8in driving wheels therefore had to be moved from Bury to the Severn Valley Railway’s workshops at Bridgnorth for turning, going back to Bury for the tyres to be fitted, before again visiting the SVR for the newly fitted tyres to be turned.
Roller bearings – Before the wheels could be test fitted to Tornado, five of the locomotive’s six wheelsets had their roller bearings fitted. The 46 different spacer, abutment, sealing and adjustment rings for the 12 Timken taper roller bearings had to be manufactured and located on the driving and bogie axles before the wheels were pressed on. The leading driving wheelset has a total of four roller bearings in two individual axle boxes. This is necessitated by the crank for the middle of the three cylinders. The remaining two driving and bogie wheelsets have two roller bearings each which are each housed in a cannon box of a tubular construction that encases the axle across the width of the frames.
The cannon and axle boxes which were cast in steel by Wm Cook Cast Products at Burton on Trent were machined by Ufone Precision Engineers at Rowley Regis, West Midlands. This work also involved welding a total of 96 pieces of highly wear resistant manganese steel to the guides in the cannon boxes which slide up and down in the horn blocks. The manganese steel liners were supplied by Aurora Metals of Sheffield. The trailing truck (cartazzi) wheelset has outside roller bearings enabling the bearings and axle boxes to be fitted after the wheels have been pressed on to the axle.
Patterns – The patterns were ordered for the piston crossheads, valve spindle crosshead guides and the cylinder covers. The most complex pattern needed for the construction of Tornado was ordered from Kings Heath Patterns of Birmingham, who produced the patterns for Tornado’s three cylinders. The pattern for the superheater header was estimated at around £9,000 to be cast in SG Iron.
Smokebox – The shell of the smokebox was now approaching completion, with the smokebox door, door fittings and ring (built by Ian Howitt at Crofton near Wakefield) assembled in Darlington Locomotive Works in readiness for fitting to the locomotive. The chimney, chimney liner and blastpipe had been cast by Charles W Taylor at North Eastern Foundry, South Shields through a very generous sponsorship arrangement. The chimney, chimney liner, blast pipe and three steam pipes were delivered to DLW following completion of machining by Ufone Precision Engineers at Dudley, West Midlands. Ian Howitt made the distinctive superheater header covers, which are fitted to the rear of the smokebox. These deceptively simple looking items would originally have been made by pressing red hot plate between male and female dies. This process was not viable for making two covers, as the tooling costs would be excessive. Instead, a single male former was made and the covers manually ‘panel beaten’ from 10mm plate using the former to create the right shape. By the the time of the annual convention the smokebox and smoke deflectors had been trial fitted, the cab was in place and the loco was “sitting” on its wheels for the first time, albeit with a large banner hanging between cab and smokebox appealing for £250,000 to fill the “gap”!
Bogie – The bogie bottom centre, end stretchers and crosshead castings were dispatched to Ufone for machining