Clan Line - A New Era Begins
13 November 1995
What was advertised as a talk on the new era
beginning for "Clan line", turned out to be two lectures on very
different, but equally important, aspects of running a preserved steam
locomotive. Firstly, we were given an insight into the research needed
to explore the market for large steam motive power. As railway
enthusiasts we tend to forget that the enthusiast market cannot sustain
the variety of rail tours which are on offer. This was a similar
message to that given by Andrew Scott was at our last lecture: "the NRM
at York has to remember that the enthusiast is only a small proportion
of its market". One of the conclusions of the MNLPS was that in order
to market "Clan Line", the locomotive had to be able to handle modern
coaching stock - and that meant air braking.
The other lecture was on the installation of the
air brakes. The original idea of George Westinghouse seemed to be
simple, but the auxiliary items result in a very complex system,
especially when it has to work with vacuum brakes. The actual design
was based upon that installed in BR diesel locomotives. It was
revealing that the cost of the actual compressor was but 5% of the total
cost. Indeed, the complexity was such that it took some time to detect
a design error whereby the various safety features prevented the system
starting up - vacuum could not be created until there was air pressure,
but the air system did not work unless there was vacuum! Another area
which had absorbed much effort was the exhaust for the air pump. This
was not a concern for the operators, but the MNLPS realised that
enthusiasts would be offended by steam coming out of the tender.
Eventually a solution was found which minimised the offending steam,
without the problems found when the exhaust was directed under the
The MNPLS did not regret having chosen to install
the air pump in the tender. The result was tucked neatly out of the way
, but was accessible for servicing. To have attempted to fit the pump
between the locomotive frames would have been much more difficult to
accomplish and maintain.
The 2 lecturers were supported by 2 other members
of the MNLPS and the evening finished off with a free ranging discussion
on a number of technical topics - like the fitting of "Buck-eye"
couplings to match Southern EMUs.