Derby Sulzer type 2, class 25/3 for OO

[Mike Parkes]

25/0s had flush fitting doors amongst other minor differences from 25/1s. I'm not sure about D5176, as that was an oddball.

Looks like it had recessed doors
https://www.derbysulzers.com/25026.html

[Pennine MC]

The answer to your second question is no. There were no class 20, 37 or 40 sub classes when they were built. Not sure about the 45s mind you.

Rhetorical question Jim. I know there weren't, it was designed to make folk think about all this 24/1 malarkey

[
25/0s had flush fitting doors amongst other minor differences from 25/1s. I'm not sure about D5176, as that was an oddball.

It's much, much easier to think of a 25/0 in terms of its body style. It's basically a late 24/1 shell that has the 1250hp engine and doesn't happen to have a boiler (though I'm sure some would have, had production continued with that body).

Puzzled (but willing to learn) why 5176 was an oddball? It was the first 25/1; why was it different to 5177/78, with which it was delivered, or any other 25/1 for that matter?

[luckymucklebackit]

But think again - how many BR diesels were differentiated by subclass according to body differences? Folk think a 24/1 is a headcoded version - it might be, but it might not. Do 20s, or 37s, or 40s or 45s have subclasses according to their headcode type?

24/0 and 24/1 relates to the electrical equipment. The 24/0 has a separate exciter on top of the main generator (like the class 15 does) where as the class 24/1 it's built in. All the preserved class 24s with the exception of D5032 are 24/1s. Bachmann still keep referring to the headcode one as a 24/1 but in reality they all ready make them.
The answer to your second question is no. There were no class 20, 37 or 40 sub classes when they were built. Not sure about the 45s mind you.

Before the TOPS classification system was introduced until 1973, everything from D5000 to D5299 and D7500 to D7677 were simply just "Derby Sulzers" or "Type 2's", you had to check the asterisk's and other hieroglyphs in the Ian Allen ABC to work out the sub-class differences, although the Eastern Region came up with a diesel classification system that recognized the power differences as early as 1962, but this system was not something that most enthusiasts referred to. There were no sub-classes in the class 40s as there were only different headcode box arrangements, class 37s as built were basically all the same design, it wasn't until after TOPS numbering was introduced that the sub classes started with the eth fitted 37/4s in the 1980s.
I remember for most classes the renumbering was straightforward, the exceptions being the class 45s, which received a totally random number order due to the creation of class 45/1 for eth and 45/0 for steam/no heat, class 47 was similar but a little less random. You really need a table to work out the pre-tops number for the peaks https://en.wikipedia.org/wiki/British_Rail_Class_45

Jim

[Mike Parkes]

Puzzled (but willing to learn) why 5176 was an oddball? It was the first 25/1; why was it different to 5177/78, with which it was delivered, or any other 25/1 for that matter?

D5176 was new to Holbeck on January 8th 1963 while D5177 and D5178 followed on February 4th 1963. Presumably D5176 had its horns fitted before the decision to fit them to the sides of the indicator box was made.

[Jim S-W]

Cant see anything unusual about D5176 here https://www.derbysulzers.com/25026.html

[Mike Parkes]

Um.. certainly has horns on the sides of the headcode boxes, looks like yet another Modern Locomotives Illustrated error

[D605Eagle]

Um.. certainly has horns on the sides of the headcode boxes, looks like yet another Modern Locomotives Illustrated error

There's a picture of it brand new with horns so they weren't retro fitted. Sadly MLI has dropped some megga gaffs. The one covering the ex class 15 carriage heating units has some terrible errors in it.