Clan Project Study

In April 2014, the Clan Project invited the AST Group to undertake a study to assess what improvements might be made to the original Clan design, with particular emphasis on improving its power and therefore its haulage (and thus money-earning) capacity.

In response, ASTT produced a detailed feasibility proposal filling 94 pages with 29 specific recommendations aimed at boosting performance to “Britannia” levels and improving reliability.  The principal recommendations were as follows:

• increase boiler pressure to 250 psi.
• a single chimney Lempor exhaust system (so as not to change locomotive’s outline).
• remove stress-raisers from the frames.
• fit multiple narrow lightweight rings to pistons and valves, including bronze ones.
• adopt direct oil injection rather than atomisation for piston and valve lubrication.
• steam-injection into primary air supply to eliminate clinkering and improve grate life

In carrying out the study, ASTT used 21st century problem solving techniques and CAD technology to suggest causes of known issues, one such being poor piston ring wear (common to several BR Standard classes) being caused by the single slidebar arrangement, resulting in piston rings being renewed on average at 10,000 to 12,000 mile intervals and exceptionally at 5,000 to 6,000 miles as compared to some other.  Other BR Standards which achieved 25,000 to 36,000 miles.  An improved slidebar support arrangement has been recommended – a solution that could also be applied to the Duke of Gloucester, Britannias and BR5s.

 

Note: The “Modernising Options”  page on this website lists part of the large repertoire of options that the AST Group has a to choose from, each one being of “tried and proven” value.