HST Grilles

[Domh245]

Something that I've been wondering about for a while. Why do some (but not all) HST power cars have a missing louvre in the large bodyside grilles, as can be seen in this picture

The fact that whenever one of these louvres is missing they are in the same place (2nd 'column' from the rear of the power car, 5th 'row' up) makes me think that it can't just be coincidental, but the fact that some power cars have it and others don't (and there doesn't seem to be any obvious pattern, such as it being TOC or engine specific) is what confuses me. Any information?

 

[Cowley]

I seem to remember there being some kind of stopcock/tap type thingy behind the gap (to do with the radiator I’d assumed)?
May be wrong though.

 

[Shaw S Hunter]

I seem to remember there being some kind of stopcock/tap type thingy behind the gap (to do with the radiator I’d assumed)?
May be wrong though.

You're not wrong. I always thought how much that little detail detracted from the High Speed image.

 

[Domh245]

I seem to remember there being some kind of stopcock/tap type thingy behind the gap (to do with the radiator I’d assumed)?
May be wrong though.

Interesting, although that still leaves the question of why some power cars have the gap and others don't. Different radiator designs perhaps?

 

[Shaw S Hunter]

Interesting, although that still leaves the question of why some power cars have the gap and others don't. Different radiator designs perhaps?

Probably down to how much attention was being paid when the power cars were re-engined!

 

[Domh245]

Probably down to how much attention was being paid when the power cars were re-engined!

But there were power cars with these gaps since at least the days of IC Swallow, so it can't be to do with re-engineing, surely. That said, wasn't there a number of units fitted with new cooling groups, which could explain the difference

 

[dubscottie]

The gap is on all ex-ECML power cars. There was a radiator filling point there and the gap is to allow the radiator to be filled during station stops.

It was added after problems with overheating in the 80's.

 

[Domh245]

The gap is on all ex-ECML power cars. There was a radiator filling point there and the gap is to allow the radiator to be filled during station stops.

It was added after problems with overheating in the 80's.

Ah, makes sense, thank you. What was it about the ECML that was causing overheating issues compared to the GWML? Longer periods of high speed running?

 

[Shaw S Hunter]

Ah, makes sense, thank you. What was it about the ECML that was causing overheating issues compared to the GWML? Longer periods of high speed running?

Longer end-to-end journeys meaning leaking radiators were more likely to be emptied en-route. The modification allowed for the use of platform based bowsers at places like Doncaster and York to top up the radiators during station calls with only a minor delay. Proper top-ups at termini was a more long-winded procedure.

 

[Cowley]

I’m purely surmising here but with the MTU programme including I think, cooler group replacement. Have these grille gaps become redundant and some have had new slats welded in and some just not bothered with?
I’m prepared to be shot down in flames if my wild claim is preposterous...

 

[Darandio]

Longer end-to-end journeys meaning leaking radiators were more likely to be emptied en-route. The modification allowed for the use of platform based bowsers at places like Doncaster and York to top up the radiators during station calls with only a minor delay. Proper top-ups at termini was a more long-winded procedure.

I'm guessing it was these coolant carts?

https://flic.kr/p/exkuhT

They were always strange little things, often repainted in the operator livery. One still stands at Newcastle I think in National Express livery although I don't believe it is in use any longer.

 

[hexagon789]

I’m purely surmising here but with the MTU programme including I think, cooler group replacement. Have these grille gaps become redundant and some have had new slats welded in and some just not bothered with?
I’m prepared to be shot down in flames if my wild claim is preposterous...

I've seen some welded slats on VTEC and XC power cars, which I assume is in connexion with what you mention.

 

[dubscottie]

Ah, makes sense, thank you. What was it about the ECML that was causing overheating issues compared to the GWML? Longer periods of high speed running?

Topography means the ECML power cars were worked harder for longer than the GW ones.

The aluminium exhaust manifolds cracked also causing leaks. 1983 was the worst year for ECML power cars shutting down because of high water temp or low coolant levels.

The aluminium manifolds were replaced with cast iron ones which solved the leaks.

 

[43096]

The gap is on all ex-ECML power cars. There was a radiator filling point there and the gap is to allow the radiator to be filled during station stops.

It was added after problems with overheating in the 80's.

It’s more complex than that - ALL power cars have coolant filling connections. The cut in the radiator grille for an extra connection was for the additional/emergency coolant tank fitted to Eastern and Scottish region power cars in the early 1980s.