While the main focus of the Strathspey Railway is running steam trains for the paying public, a small but dedicated group of volunteers has been restoring other items of heritage interest in spare moments between working on the loco fleet and improving locoshed infrastructure and facilities.

The current project is a Ruston Hornsby 48DS diesel shunter of 1948 which worked at Longmorn distillery until 1980 (even though Dr Beeching had closed the adjacent main line in 1967). Because it was presented to the Strathspey Railway repainted with advertisements for Queen Anne blended scotch whisky, it is known to most people as “Queen Anne”.

To find out more about our aims, follow this link or click the [About] button above.

This Blog was started over 5 years after the project began, so most of the initial blog entries are retrospective.

Sunday 3 December 2023

Gearbox Refurbishment - Part 3

More Pictures

Here are some more photographs of the internals of the gearbox.

Clutch drum and various bits

Detail of the clutch operating levers

Fast Gear

The fast gear clutch connects the input and output gears (1 to 1 ratio).  The friction plate is gripped between a fixed plate that is part of the clutch drum and a moving plate connected to one set of operating levers. 

The friction disc with its linings

Clamping plates either side

The fast gear friction plate

The brown discolouration of the fast gear friction plate is probably due to oil staining and not due to overheating.

Slow Gear

The slow gear clutch shows signs of overheating on various parts.  The spindles that operate the clamping plates are also discoloured at a place where they are adjacent to the slow gear clutch.  The blue colouring indicates that at some time the steel has been heated to around 290 degrees centigrade.


Slow gear clamping ring

Slow gear friction plate and spindles

The other side of the slow gear friction plate

New Friction Linings

 Investigations are ongoing regarding replacement of the friction linings.  There is a company in Cumbernauld that undertakes this type of work.  In fact they have relined a Ruston 48DS gearbox for a group at Prestongrange Mining Museum.

Another group restoring a 48DS at the Chasewater Railway has also given some useful advice.

It has not been decided yet if riveting or bonding of the friction plates is the best solution.


Tuesday 7 November 2023

Gearbox Refurbishment - Part 2

Gear Assembly Removal

 To remove the gear assembly it was first lifted manually using rope and steel bars sufficienty to enable two poles to be inserted underneath and raise it slightly above the casing.

After that, Queen Anne was towed outside to allow removal via the cab entrance using a forklift.  Strops were used to attach the assembly as closely as possible to the tine of the forklift.  The lower part of the cab entrance is too narrow for the gear assembly to pass through, but it will fit through the upper part.  However it needs to be lifted to the full height of the cab.

Forklift in position

Strops attached

Have we got enough clearance?

Out it comes - no problem


The assembly was then lowered onto a sturdy trolley and wheeled to the Clean Room for dismantling.

Dismantling started


A gear puller was required to remove the ball bearing and roller bearing that form the rear bearing assembly.  Following that the gears can be slid off and the rear face of the clutch drum unbolted.

The next part to be removed is the clutch friction plate for Slow Gear.  On removing the rear face of the clutch drum the friction material was found to have completely disintegrated.  The clutch disc should have a ring of friction material on both sides, held in place by brass rivets.  In fact both friction rings had deganerated into a fibrous mass.  It is amazing that Slow Gear could be made to supply any drive at all.

It seems likely that the locomotive must have been run for some time in Slow Gear with the clutch slipping, causing overheating and breakdown of the friction material.

Friction plate showing the rivets which once held the friction material


The remains of the friction material

Clutch rubbing plate

To engage slow gear the friction plate is squeezed between the moveable rubbing plate (pictured above) and the rear cover of the drum assembly.

A useful description of the operation of this type of gearbox can be found HERE.  It contains colour-coded diagrams showing how power is transmitted in each gear.  The website is run by the Moseley Railway Trust.

Sunday 29 October 2023

Gearbox Refurbishment - Part 1

Clutch Problems

The Ruston gearbox fitted to Queen Anne has three gears - slow, medium and fast.  The different gears are in constant mesh, but each ratio has its own friction plate clutch.  Gear selection is achieved by engaging the appropriate clutch via the gear change lever.
We have known for some time that slow gear is not very effective - its clutch slips.  There is an adjustment for the spring that applies pressure when the clutch is engaged but while this can make the clutch more effective the resulting pressure is obviously excessive.  The friction plates are riveted to steel disks and it is very likely that the friction material for slow gear has worn down to the rivets.

The replacement of the friction linings is part of normal maintenance for this type of gearbox and is described in the locomotive manual.  Other restoration groups have carried out this work and there are companies who specialize in relining friction plate clutches for heritage vehicles.

The whole gear assembly can be lifted out once the gearbox cover is removed and the assembly stripped down on the bench.

Gearbox Cover Removal

Queen Anne has been kept in the carriage storage shed recently so the first step was to get her moved into the locoshed.
Queen Anne being manoeuvred into place

On Road 4 ready to start work
The first step is to remove the central floor sections - no problem as they are now secured using stainless steel screws/bolts.  Then the gear change unit must be unbolted from the side of the gearbox.

Central floor removed

Once all the nuts and bolts for the gearbox cover have been removed lifting eyes are screwed into the two positions on the top of the cover.  Because the cover weighs 3 cwt it was decided to use two steel bars and four jacks to lift the cover off.  Since the cover needs to be lifted to at least cab floor level, this required "jacking and packing" using wood blocks.

Jacking system in place

Packed up with wood blocks

Poles inserted underneath the cover

Once the cover had been lifted high enough, poles were rolled underneath and the cover lowered onto them.  The cover could then be slid sideways to sit on the floor at the left-hand side of the cab.

The gearbox mechanism

The above picture shows the gearbox assembly.  From left to right, the main components are :-
  • The output gear to the forward/reverse box.
  • Bearing.
  • The input gear from the drive shaft in the gearbox casing.
  • Fast gear clutch operating ring. 
  • Medium/Slow gear clutch operating ring.
  • Drum containing the clutch plates.
  • Gears providing the different ratios.  The lay gear for this can be seen underneath.
  • Bearing.
As can be seen, the whole assembly simply lifts out.  Further updates will be published as work progresses.

Monday 24 April 2023

Chain Oiler and Diesel Gala

The Chain Oilers

The chain oilers have finally been completed.  A drip-type oil pot is attached to a solenoid valve which is energised while the engine is running.  A pipe feeds the oil to a special brush which is mounted on an adjustable arm to spread the oil over the chain.  There are two separate oilers, one for each chain.

The brushes need to be mounted close to the sprocket on the reversing gearbox.  In any other position they would be vulnerable to the chain whipping or movement of the suspension.  There is not much room near the sprockets so mounting them is tricky.

The following photographs show the setup.
An oil pot with its solenoid valve

The LH brush. A very cramped location.

RH brush showing the adjustable mounting arm

Excess Fuel Device

In order for the engine to start (especially when the engine is cold), it is usually necessary to squirt more fuel than normal through the injectors to get it running.  To do this a device is fitted to the control rod that regulates the fuel injection pump.  This device is a brass casting with lugs that is lifted up to allow the control rod to move forward and inject more fuel.  Once the engine is up to speed, the governor pulls the control rod back and the device drops down to its working position, limiting the maximum amount of fuel delivered.
Often the engine will start to fire and pick up speed causing the device to drop back, but the engine still needs to warm up a bit more and so the engine stalls.  If the device is lifted up again the engine will pick up speed and eventually run on its own.  Except in very warm weather it needs to be lifted two or three times before the engine will run on its own.

The problem with the original arrangement is that the device is not visible unless you peer inside the engine compartment, so you have to feel for it.  The device is close to the fan belt and other moving parts, so you need to know exactly where the device is.  For this reason it was decided to make an accessible lever to operate the device.  A bracket bolted to the engine block was modified to take the new lever and a flexible steel wire was used to pull up the lug on the excess fuel device.

So to start, all you have to do now is to open the right-hand bonnel door and pull down the lever before starting, and possibly pull it down once or twice more until the engine runs freely on its own.

The new excess fuel lever on the front of the engine

The brass casting and its lug is shown in the circle

Diesel (mixed traffic) Gala 2023

This year's Diesel Gala (7th to 10th April 2023) had Queen Anne offering footplate rides in Aviemore yard.  Things were a lot quieter than the 2022 Gala but those that came on board seemed to enjoy the experience.

Queen Anne also did a couple of "taxi rides" to Aviemore station - a first for the loco.  Here are some photos of the event :-

Queen Anne and the Class 31

Class 37 approaching

In the loop at Aviemore Station

And a video on Youtube :-

Queen Anne also features in some other Youtube videos of the Gala.  See the "Queen Anne Videos" page above for links to these.