Introduction
In May 1997, The Heritage Lottery Fund awarded the Trust a grant of £233,800 towards the cost of carrying out a heavy general overhaul and a programme of modifications totalling £338,759. This gave the Trust, the opportunity to take 'The Duke' a stage further, and show just what the locomotive could achieve. The "real - life fairy tale continued".
Increasing The Tender Water Space
The first modification was intended to go some way to addressing the difficulties encountered in taking water en route during railtours. The top rear part of the tender had a lot of unused space and this was chosen as the best place to incorporate more capacity for water.
An extension was incorporated which increased the water capacity from 4725 gallons to 5100 gallons and which would extend the distance between waterstops from about 80 miles to 92 miles.
In fact, by the time the heavy general overhaul was half way through, the difficulties encountered with taking water on the main line had increased to such a point that Trust engineers considered that this water increase would not be sufficient to cope with the perceived operational difficulties. Another solution had to be found.
One other change was made when the tank modification was carried out. The single ladder on the rear left hand side of the tender was replicated on the right, to enable support crew members to get to the tank top from both sides in safety.
Steam Operated Coal Pusher
'The Duke' was fitted with two slightly different tenders in BR days - both with 10 tons of coal and a steam-operated coal pusher. At Barry scrapyard it had no tender at all. In restoration, a similar tender was modified to replicate the original type, but no consideration was given to manufacturing and fitting a coal pusher This was because no-one imagined that steam engines would be running under overhead electric wires for any distance ever again. However, in 1995, 'The Duke' ran several times for more than 200 miles "under the wires", and the firemen were not allowed to go into the tender to pull down the coal, because of the risk of electrocution. No "trimming" of coal was allowed at waterstops for the same reason. This rendered about 4 1/2 tons of coal irretrievable in the rear of the tender and support crew members had to attempt to alleviate it by carrying coal in the support coach. This was not satisfactory and it became obvious that a coal pusher was the only answer.
In the beginning, only the arrangement drawing was available to the Trust, and during the project only four other originals came to light. The component drawings were made by Riley and Son (E) Ltd. from the stripped down coal pusher from 46229 Duchess of Hamilton. These were added to by Cerdic Foundries of Chard who made the castings and were subsequently adjusted for machining purposes.
The result of these endeavours is the first steam operated coal pusher to be made and fitted since 1955.
.jpg "The Coal Pusher Patterns")
.jpg "The Coal Pusher Castings")
British Caprotti Valve Gear
When 'The Duke' was first built in 1954, Tom Daniels, Chief Design Engineer for Associated Locomotive Equipment Ltd offered British Railways the choice of two exhaust cam profiles, giving different release events. After deliberation they opted for the profile giving an earlier release event. Had 'The Duke' been more of a success in BR days the exhaust cams with profiles giving a later release event might have been substituted. Now such cams have been made and fitted to all three camshafts of 'The Duke'. They will keep the exhaust valves closed for a longer period in the cycle, giving even greater cylinder efficiency than before.
Ashpan Air Spaces
After correction of the front damper air spaces in restoration, no further need for research in this particular aspect of combustion was considered necessary. However, in main line running, recurring serious problems were encountered with melting firebars and clinkering of the fire (fusion of the iron in the coal with the metal of the bars) at the rear of the firegrate. Investigation of the problem led Trust engineers to believe that more air was required through the rear of the ashpan.Thus when a new ashpan was manufactured to replace the life-expired one made in restoration, the single centre rear damper was supplemented by two outside ones, giving increased volume of air and better flow to the rear of the grate.
Air Braking
In the days of steam traction on British Railways, the locomotives were fitted with vacuum-operated train-braking equipment. In todays world all traction is fitted with air-braking and for steam to continue to run on the main line, a change of braking systems is necessary. However, while vacuum braking is simple, air braking involves a huge amount of equipment and is thus expensive to fit. 'The Duke' has been equipped with an ex-Polish Railways steam operated air compressor, which was completely overhauled by Trust engineers before fitting.
Very little of the new equipment can be seen on the locomotive and tender and appearances are not affected. 'The Duke' still retains the equipment which will enable it to pull vacuum-braked trains on Heritage Railways.
