FEATURE MODEL March 2013
Ian Fanshawe:  British Class 7 Locomotive

Ian Fanshawe has recently completed his model of a British Class 7 locomotive.  As well as being beautifully built it has some interesting and unusual features.

The model is based on a British Railways Class 7 Locomotive.  These were referred to as Britannia’s after the name of the first of the batch of 55 produced.  However the model  does differ in terms of the valve gear.   During the design phase of the standard Class 7 locomotives in the late 1940’s, it was proposed to fit them with Caprotti poppet valve gear.  This was never done and Walschaerts piston valve gear was used instead on all 55 of the class numbered 70000 to 70054.

The Caprotti valve gear was however used with some success on the later Class 8 (Duke of Gloucester) and many of the Standard Class 5’s.  The gear had many advantages in reduced maintenance and virtually doubled the cylinder efficiency on these locos.  It is proposed therefore that if there had been any further batches of Class 7’s then the Caprotti gear would have been employed and the loco number 70055, used on the model, reflects the 1st of this possible second batch which never actually happened.

The name “Robert the Bruce” follows the trend in naming the Class 7 engines after well-known historical British people.  He was the king of Scotland in the early 14th century and the train head board “The Royal Highlander” fits nicely with the loco name.  This train used to leave London Euston every evening and was the overnight sleeper to Perth, often being pulled by a Britannia.

As if a project like this is not enough of an undertaking, Ian also had to deal with the effects of the Christchurch earthquakes.  Unfortunately Robert the Bruce toppled off his stand sustaining damage.  Picking up a 350kg locomotive is no easy undertaking let alone seeing the damage to your pride and joy.

Model Details:

Gauge 7 1/4"

Weight 350kg

Length                                     2.8m

Height                                     510mm

Width                                      390mm

Boiler Working Pressure        100 psi (690 kPa)

 

Click on the link below to see a YouTube Video of "Robert the Bruce"

 

 

The newly machined Camboxes

The completed cambox (without the cover).  See video below for its operation.

 

MOV00503.MPG MOV00503.MPG
Size : 1531.687 Kb
Type : MPG

 Click on the link above for video of testing the running gear

 and the valve arrangements

MOV00502.MPG MOV00502.MPG
Size : 1654.82 Kb
Type : MPG

Click on the link above for video of testing the running gear

 and the valve arrangements