How it works

How it works


A steam engine is basically a method of turning pressurised steam created in the boiler into forwards and backwards motion via means of pistons and connecting rods to the wheels. However, a locomotive such as General Steam Navigation takes the basic principles to create a complex design to create power and efficiencies.

These pages aim to provide an overview of some of the design features incorporated within General Steam Navigation. 


Click on the links below to find out more:


Basic Steam Engine Principles


Click here to discover the basis principles of a steam engine.


The Bulleid Boiler


The Bulleid boiler design was a highly efficient steam raiser and “generally recognised as the best of all pacific boilers”. Read more about the design here.


Bulleid's chain Driven Valve Gear


The purpose of the valve gear on a steam locomotive is to control the flow, direction and amount, of steam passing into and out of the cylinders, Bulleid's innovative chain drive valve gear is described here.


Bulleid - Firth - Brown Wheels


One of Bulleid’s most instantly recognisable features on his Southern Railway locomotives are his BFB wheels.

They are described in more detail here.  


Trailing Trucks 


There were two designs of trailing trucks fitted to Bulleid Merchant Navy pacifics, our 21c11 / 35011 is unique amongst those  preserved in being itted with one of the fabricated type of trailing truck. 

Read more about the two types of trailing truck here.  


Electricity Generation, lights and Engine Headsignals


Another recognisable feature of Bulleid pacifics was the electric lamps fore and aft and also within the cab. Electricity was generated on board by a “Stones steam generator”. 

Read about how the system worked here.