Spa Valley Railway, West Station, Royal Tunbridge Wells, Kent, TN2 5QY
Telephone: 01892 537715
Email enquiries@spavalleyrailway.co.uk

Axlebox Overhaul of 47493 - Winter 2005 - 2006

In late 2005, 47493 was withdrawn from service for an axlebox overhaul to eliminate some minor knocks that had appeared during the season. The work centred around re-metalling the axlebox thrust faces and horn guides, as well as the bearings. The aim is to reduce the amount of side float in the driving (centre) axleboxes to prevent the knocks from continuing and getting any worse. The work was completed in the first half of 2006 and the engine returned to service on the 16th July.

December 13th 2005

After three or four weeks preparation work since the engine was withdrawn from service, two cranes were hired to lift 47493 from its wheels. This was the first time that this method was used, as in the past, jacks and timbers have been the preferred option. However this takes a number of weeks, where is the cranes completed the whole lift in 10 minutes. 

The locomotive has been placed on a set of bogies whilst the wheels are out from under it. These bogies are off a flat wagon and have allowed the engine to sit at a similar height to what it normally would on its own wheels.

All photos M. Dives

December 17th 2005

Left:- Work soon started with the axleboxes being removed and the wheels cleaned down to receive a fresh coat of paint (left). Photo M. Dives

The axleboxes then had all their white metal run melted out and all components were placed in a caustic bath to remove the remaining oil. The first of the boxes were then tinned in early January, in preparation to receive the fresh white metal.

January 24th 2006

Tinning well under way on the axleboxes. This aided the whitemetal to stick to the boxes. The process involved using four propane burners, placed all around the axlebox, which brought the temperature up evenly. Three faces required tinning, the thrust face (the one on top in all photos) and the two horn guides (axlebox sides). The bearings themselves, which fit inside the boxes, were re-metalled separately.

This method allowed two or three boxes to be tinned in a day. 

All photos:- The tinning process underway. The propane burners can be seen in action heating the axlebox ready for the tinning to be added - All photos D. Skinner

January 30th 2006

By the following weekend, white metalling had commenced on the horn guides. This involved setting up a mould in which the molten metal would be held until it solidified. During this weekend, 4 horn guides were metalled. This only left 8 more horn guides, 6 thrust faces and the bearings to metal. Not a lot on paper, but time consuming when actually doing the task.

Above:- The white metal is poured into the horn guides. The clamps are holding the pre-made moulds in place whilst the molten metal solidifies - Photos M. Dives

February 9th 2006

Above:- The burners heat the axlebox up to the required temperature (left), ready for the pouring of the thrust face. And the final product (right) - Photos M.Dives

The next task was to re-metal the thrust face. This area rubs against the wheel and prevents the wheelset from moving sideways too much when in the axlebox. The temperature for this pour was critical as it had to be enough for the white metal to adhere to the axlebox, but not too much so that it ran the metal which had been poured into the horn guides a week previous. Work centred on getting a complete pair of axleboxes finished before starting on the other four, so that the machine shop could set up the machine and begin machining at the earliest opportunity.

Problems were encountered with the mould for the bearing itself and this had to be modified so metalling of these was put on hold.

February 13th 2006

A new mould for the bearings was made and two were successfully metalled. This allowed the first two axleboxes to be assembled and taken to the machine shop where the machine was set up, and the task of machining was started. 

Above: The first axlebox on the machine where the first cuts have been made on the thrust face, whilst the second completed box waits on the floor - Photos M. Dives

February 19th 2006

Work continued on machining the axleboxes, with work moving on to boring the bearing surface itself. White metalling continued and in one day, it was possible to undertake 6 individual pours which involved a lot of setting up in between. By the end of the weekend, there were only two more thrust faces left to re-metal and two more axleboxes were complete.

February 28th 2006

Machining of the first axlebox was completed on the thrust face and bearing. The horn guides were put on hold as the machine  needed to be set up differently to do this. A start on the second axlebox was made.

April 3rd 2006

Work on machining the thrust face and bearing of the fifth axlebox was underway, with one more and the twelve horn guides still to do. Work on putting the other components back on the engine is being started.

April 10th 2006

Above Left:- The fifth axlebox in the milling machine having the bearing surface turned down. 
Above Right:- One of the completed axleboxes on the bench. This is one of the leading axleboxes which was started first, and all that was left to do was the machining of the horn guides - Photos M. Dives

With machining of the thrust faces and bearings almost complete, attention has now turned to measuring the axlebox horns. This involves using V-Blocks and setting them up with a straight bar in between to simulate the centre of the axle. Measurements were then taken from the centre of the axle to each horn cheek, and with the help of some works drawings, the amount required to be removed from each horn guide was worked out. 

Above Left:- The V-Blocks set up in the Driving axlebox horns. The steel bar is seen running between the two horns. This was set up so that it was square to the frames and exactly in the centre of the space. This then simulates the position of the axle when it is returned to the frames in the axlebox. Measurements were then taken from the bar to each horn cheek so that the machine shop knew how much material to take off.
Above Right:- Work progressing on painting the wheelsets. The driving axle is seen stripped back to bear metal - Photos M. Dives

April 18th 2006

All the thrust faces and bores were completed, but measurements were still underway on the engine, preventing machining of the horn guides to commence.

May 9th 2006 

Work on the horn guides was almost completed with only a couple of weeks work left to do. One bearing had been re-metalled as machining had revealed improvements that were needed. Painting of the wheels was progressing with one set in undercoat.

Above Left:- A completed axlebox resting on the bench in the machine shop. All that was left to do was remove the fire clay from the underkeep pin holes - Photo M. Dives
Above Right:- Another of the axleboxes on the milling machine, having a horn guide machined - Photo M. Dives

Above:- The driving wheelset painted in green primer - Photo M. Dives

June 16th 2006

The first of the axleboxes were scrapped in for the final fitting to the axle. Two axleboxes were completed, with one fully fitted onto the axle. The wheels had received at least one coat of top coat, with another to follow. Preparations to lift the engine were beginning to be made, this time through the use of Matterson jacks. At this point, the engine was less than a month from its eventual return to service.

Left:- The first completed axlebox back on the an axle. This was one of the leading axleboxes. The underkeep pins then added and all that was required was the spring - Photo M. Dives

June 19th 2006

All the bearings were finally scrapped in and fitted into the axleboxes. This was followed soon by a frantic afternoon of fitting the boxes on to the axles, fitting the underkeeps, underkeep pins and the springs. The final result was six shiny axleboxes all fitted to their respective axles. This was just in time, as the jacks were due to arrive the following weekend, which with all going to plan, signified the beginning of the marathon job to re-assemble the engine ready for its annual steam test and return to service.

Above Left:- The end of the day on the 18th June and all three axles have their axleboxes and springs re-fitted - Photo M. Dives
Above Right:- The driving axle showing the re-fitted axlebox and spring - Photo M. Dives

June 27th 2006

On the 24th June, Andrew Goodman was hired to bring his set hydraulic jacks to lower the Jinty back on to its own wheelsets. In a matter of time on the Saturday, the Jinty was lifted from the bogies, which had been its home for seven months, and lowered back on to its own wheels. This was closely followed by the fitting of the horn stay, springs and side rods after the wheels had been set. The engine then returned to the shed so that the remainder of components could be re-fitted.

Above Left and Right:- The Jinty up in the air, although this time on jacks. The freshly overhauled wheelsets are under the locomotive whilst one of the bogies is removed - Photo M. Dives
Below:- Shortly after, the Jinty sits back on the ground on its own wheels once again. All that remained to do was re-fit the side rods - Photo M. Dives

Early July 2006

Less than two weeks after the engine had its wheelsets re-fitted, the Jinty was out on the line on running in turns. A few axleboxes ran warm, although these were treated with care and constantly fed with oil.

Left:- The Jinty passes through Groombridge station on a running in turn. This was one of its first trips to Groombridge in 2006 - Photo T. Harrison

July 15th 2006

D-Day. The Jinty was returned to service so that it could haul some trains over the Wings, Wheels and Steam event with Groombridge Place. The engine hauled four trains on its own and revealed few problems, which considering it had few miles under its belt after such a major overhaul, was excellent. In fact, as the day went on, the problems got better with the more miles the locomotive ran. 

Left:- As if it was never away! 47493 passes the P-Way gang just beyond Poke Hill Farm crossing, as it begins its climb towards Tunbridge Wells - Photo P. Reynolds

Last Updated 24th January 2007. ©M. Dives