In my previous post, I wrote a little about the early development of locomotives on the Liverpool and Manchester (L&M) railway, culminating in a series of standard engines, built ‘in house’ and called the Bird-class.

 

In the process , I realised that not all railways have generated a literature that describes every detail of their locomotives, so that it has needed considerable effort to find sufficient information to construct a model of ‘Ostrich’.

 

My main source of information was ‘The Locomotives of the Liverpool and Manchester Railway’ by Anthony Dawson. From that, I learned that the Bird-class engines were fitted with a type of gab-gear devised by William Buddicom, who was the resident engineer of the L&M at their Edge Hill works during the period 1836 – 8.

 

After some research, I found a diagram of Buddicom’s gear on the web at http://onhistoricallines.blogspot.com/2016/11/on-valves-and-gears.html   I have coloured various parts to clarify their functions.   

 

Diagram of Buddicom Valve Gear

 

Of course, a diagram of this type provides no information about the disposition of the parts across the width of the engine.

 

There is, however, one locomotive from this period of the L&M that is well-documented: ‘Lion’ was built by Todd, Kitson & Laird and delivered to the L&M in August 1838. It was withdrawn from service in 1859, when it was purchased by the Mersey Docks and Harbour Board for use as a stationary pumping engine. It was re-discovered there in 1923 and restored at the Crewe railway works, after which it took part in the centenary celebrations of the Liverpool and Manchester Railway in 1930.

 

‘Lion’ has since steamed again on a number of occasions and was used during the filming of ‘The Titfield Thunderbolt’ in 1953. In 1979, ‘Lion’ was again restored to working order in time to lead the cavalcade on the first day of the Rocket 150 celebrations at Rainhill. As a ‘celebrity’ engine, it has received far more attention than any other locomotives from that period of L&M operations.

 

Although ‘Lion’ was originally fitted with Melling’s radial gear, it was found to have been re-fitted with Buddicom’s gear at some stage of its working life. I found a detailed description and diagram of the valve gear fitted to the restored ‘Lion’ in an article published in ‘The Engineer’, Vol.150, no 3095, dated Nov.14th, 1930.

 

'Lion' drawing from 'The Engineer' 1930

 

It is clear that the arrangement of the lifting links on ‘Lion’ differs from that shown in the generic drawing of Buddicom’s gear. This raises the question of how were things done on ‘Ostrich’?

 

Fortunately, the illustration of ‘Ostrich’ that I showed in my previous post includes part of the motion below the footplate. By laying the illustration from ‘The Engineer’ next to that of ‘Ostrich’, I was able to identify corresponding components from the two drawings.  I have coloured parts of these diagrams to match those used on the diagram of Buddicom’s gear, above.

 

Comparison

 

Because a lot of the motion is hidden behind the wheels and footplate of ‘Ostrich’ my interpretation has to be somewhat speculative. It does, however strongly suggest that the eccentric rods were lifted from below, as in the case of ‘Lion’, rather than as shown in the diagram of Buddicom’s gear.

 

Additional assistance for creating a model came from the ‘Resources’ section of the ‘Old Locomotive Committee (OLCO) blog’ https://lionlocomotive.org.uk/ from which I have drawn on two photographs, shown below.

 

Photos of ‘Lion’ from OLCO Resources https://lionlocomotive.org.uk/

 

Creating a 3D-Model

 

After that pre-amble, I feel I now have enough information to attempt to add the motion to my model of ‘Ostrich’.

 

I decided to start with the crank axle and the rest of the main drive train. The first item I drew was the ‘pair of spectacles’, as seen in the underside photo of ‘Lion’. Of course, I cannot be sure that ‘Ostrich’ had the same fitting but it seems to be a reasonable assumption.

 

I continued to use 'The Engineer' drawing of ‘Lion’ for several other components. Each component was extruded separately, as shown below, and then assembled together:

 

3D Modelled Motion Components

 

 

Now, I could place all these parts in their proper locations within my 3D model of ‘Ostrich’

 

3D Model of ‘Ostrich’ Drive train

 

Valve Gear

 

In modelling the valve gear, I adopted the same approach as for the drive train. I started by extruding parts from the drawing of the ‘Ostrich’ valve gear, shown above. My 3D model of a pair of eccentric rods is shown below:

 

3D Modelled Eccentric Rods

 

In order to determine the arrangement of the gear across the width of the engine, I turned to the drawings and photos of ‘Lion’ for guidance.

 

Locations of Eccentrics from ‘Lion’ drawing

 

Now I started a lengthy and rather slow process of working out where all the shafts and linkages should go!

 

I broke the task down into small chunks – remembering @Mikkel dictum about how to eat an elephant.

 

1st Bite: I made the cross shaft and its two curved support brackets that are visible in the side elevation of ‘Ostrich’. I then added the levers that lift the forked ends of the two eccentric rods on one side of the engine (LHS) From looking at the various photos, I could see that the lower eccentric rod rested in a forked end of its lifting link, while the upper rod was supported from one side. This difference was necessary to avoid blocking access to the gab in the down-turned forks on the eccentric rod.

 

2nd Bite: The purpose of the lifting links is to move either the forward or the reverse eccentric to engage with the rocking lever, which rotates the ‘weigh bar’. At its outer end, the weigh bar carries another lever which transfers the motion of the selected eccentric to the valve rod.

 

3rd Bite: The two eccentric rods are attached by means of straps to a pair of eccentrics mounted on the driving axles and arranged to open and close the valves as appropriate for the direction of travel.

 

4th Bite: Once I had created the ‘motion’ for the left-hand valve, I used the ‘mirror’ command in ‘Fusion’ to duplicate the motion for the right-hand valve.

 

These successive ‘bites’ are illustrated below:

 

 

Four steps in creating my 3D model of the valve gear

(various support structures omitted for clarity.)

 

Once these steps had been completed, I restored some of the drive train components that I created earlier:

 

3D model of valve gear with slide bars and cross heads added

 

And so, I can now restore the various brackets that support the ‘loose ends’, to give an overall view of Ostrich’s undergear:

 

 

My 3D model of ‘Ostrich’ undergear

 

That has been an intensive task, involving a lot of interpretation of the available drawings and making some assumptions about the relationship between ‘Ostrich’ and ‘Lion’; the latter engine being better documented.

 

My 3D Model - underside view of ‘Ostrich’

 

Sadly, after all that mental effort, not much is visible from normal viewing positions– at least I know it’s there 🙂

 

My 3D model of ‘Ostrich’, including the Buddicom valve gear

 

So, I have started the New Year with a model of a little-known prototype from the Liverpool and Manchester Railway. Where next, I wonder?

 

Mike