Silencer problems on class 37/9's.

[musicindetail]

Hi all, I'm curious to know why the silencers were removed from the class 37/9 locos. I've read that, with the exception of 37902, which kept hers right through to withdrawal, all the others lost their silencers within 3 years of conversion to 37/9.

Excuse my ignorance on this subject, but would the removal of the silencers have a knock-on effect on the loco's power output? The nickname 'slugs' suggests that it might have.
Thanks, Tony.

 

[Richard Scott]

Hi all, I'm curious to know why the silencers were removed from the class 37/9 locos. I've read that, with the exception of 37902, which kept hers right through to withdrawal, all the others lost their silencers within 3 years of conversion to 37/9.

Excuse my ignorance on this subject, but would the removal of the silencers have a knock-on effect on the loco's power output? The nickname 'slugs' suggests that it might have.
Thanks, Tony.

Can't remember why silencers were removed but the slugs nickname came from the fact that there was a choke in the air pipe from power controller to the governor. This meant the engine was slow to respond to driver request for increased power as air pressure took a while to build to get the governor to open up the fuel rack and hence increase fuel supply to the engine.

 

[Cowley]

Can't remember why silencers were removed but the slugs nickname came from the fact that there was a choke in the air pipe from power controller to the governor. This meant the engine was slow to respond to driver request for increased power as air pressure took a while to build to get the governor to open up the fuel rack and hence increase fuel supply to the engine.

Nicely explained. Thanks for doing that.

From a layman’s point of view they definitely seemed to take an age to reach full revs, however they would eventually get there, and once wound up they seemed to be pretty decent performers on heavier trains. Maybe not comparable to 47901 vs the rest of the standard class 47s (which I think is how they’re compared sometimes). But still pretty solid in day to day traffic.

 

[33017]

Hi all, I'm curious to know why the silencers were removed from the class 37/9 locos. I've read that, with the exception of 37902, which kept hers right through to withdrawal, all the others lost their silencers within 3 years of conversion to 37/9.

Excuse my ignorance on this subject, but would the removal of the silencers have a knock-on effect on the loco's power output? The nickname 'slugs' suggests that it might have.
Thanks, Tony.

Doesn’t the removal of a silencer improve rather than restrict power?

 

[musicindetail]

Can't remember why silencers were removed but the slugs nickname came from the fact that there was a choke in the air pipe from power controller to the governor. This meant the engine was slow to respond to driver request for increased power as air pressure took a while to build to get the governor to open up the fuel rack and hence increase fuel supply to the engine.

== Doublepost prevention - post automatically merged: 23 Dec 2023 ==

Thanks for the information Richard, I appreciate it. I only wish I had more technical knowledge, I find this subject fascinating. Mind you, my Daughter tells me I'm still struggling with light switches!

 

[D365]

is 37901 (Europhoenix) still missing the silencers?

 

[musicindetail]

is 37901 (Europhoenix) still missing the silencers?

Judging by the engine sound when I last saw her, yes, she is still without them.
I was fortunate enough to hear 37901 working hard on heavy coal and steel trains here in South Wales shortly after conversion to a 37/9. She was incredibly quiet, given the weights and gradients she had to contend with. Sadly, toward the end of her career, despite the hard work of the Cardiff Canton engineers, she became increasingly unreliable, with engine temperature issues and other problems, including 2 fires, one of which I'm told occurred deep in the Severn Tunnel. The loco was repaired, but a Driver who drove her regularly told me that she had become effectively useless on steep gradients, because of ongoing engine over-heating problems. She was withdrawn shortly after that conversation.

 

[Richard Scott]

Judging by the engine sound when I last saw her, yes, she is still without them.
I was fortunate enough to hear 37901 working hard on heavy coal and steel trains here in South Wales shortly after conversion to a 37/9. She was incredibly quiet, given the weights and gradients she had to contend with. Sadly, toward the end of her career, despite the hard work of the Cardiff Canton engineers, she became increasingly unreliable, with engine temperature issues and other problems, including 2 fires, one of which I'm told occurred deep in the Severn Tunnel. The loco was repaired, but a Driver who drove her regularly told me that she had become effectively useless on steep gradients, because of ongoing engine over-heating problems. She was withdrawn shortly after that conversation.

The locomotive was purchased for preservation and I did have a look around it and was there when it was first started in preservation. If memory serves me right the engine was deemed unusable for reasons that escape my memory and the one from 37904 substituted.