The first question is related to the tanks and fillers of a refurbished engine.
Who knows where this will end up... not me forsure!]
This question about the tanks fitted to a refurbished engine arises from books with information on construction details as built and as refurbished. Whilst there seems to be general consensus about what was provided for initial build and the result of refurbishment there is no clear story about what was retained / replaced / converted - maybe that is not possible at this distance in time.
Locos which were built with steam heat boilers had a diesel fuel tank and a water tank, no problem. Locos which were built without a steam heat boiler would not have requried a water tank so there are several possibilities:-
 water tank provided and not used;
 water tank not fitted and nothing else put in vacant location;
 water tank not fitted and second fuel tank fitted as replacement for water tank;
 water tank fitted and converted for use as a diesel fuel tank.
Locos which were refurbished as Cl 37/4 were given electric train heat capability and hence would not have required either a steam heat boiler or a water tank. If an engine with a water tank was included in the refurbishment program then upon release as a 37/4 what was the situation:-
 water tank retained and converted for use as a diesel fuel tank;
 water tank replaced by a fuel tank for diesel fuel.
There may be other scenarios which could be included in this question, however my interest is specific to the appearance of engine no. 37408 circa 1988. As this engine was built without a steam heat boiler then the staring position is relevant.
To continue. Instinct suggests that a filler for a water tank ought to be of a different shape / size to a filler for a fuel tank - so as to avoid water being put in a fuel tank and vice versa. If that is correct then what was done to on refurbishment if a water tank was converted to a diesel fuel tank? (changes to the fillers? to the tank?)
Not having seen the respective fittings of a 37, night anyone have photos of the water and fuel fillers?
thank you for your assistance, Graham Beare
Edited by Western Star, 06 February 2012 - 16:14 .