• Our booking engine at tickets.railforums.co.uk (powered by TrainSplit) helps support the running of the forum with every ticket purchase! Find out more and ask any questions/give us feedback in this thread!

Overshoot at St Austell?

Status
Not open for further replies.

notadriver

Established Member
Joined
1 Oct 2010
Messages
3,653
Does anyone know anything about an alleged overshoot last night at St Austell?
 
Sponsor Post - registered members do not see these adverts; click here to register, or click here to log in
R

RailUK Forums

Rich McLean

Established Member
Joined
6 Feb 2012
Messages
1,685
It happens, especially with the composite brake blocks now fitted to Mk3 stock combined with poor rail head conditions that we have had in this wet weather.

Expect more of this sort of thing over the up and coming leaf fall season
 

TDK

Established Member
Joined
19 Apr 2008
Messages
4,155
Location
Crewe
It happens, especially with the composite brake blocks now fitted to Mk3 stock combined with poor rail head conditions that we have had in this wet weather.

Expect more of this sort of thing over the up and coming leaf fall season

Brake blocks are a lot better than disc brakes in leaf fall/low adhesion as they clean the wheels. The low adhesion recently has been minimal and to be fair an over run at this time of year is seldom diagnosed to be because of poor adhesion. You get a lot more brake fade with brake blocks than disc brakes and as a driver take this into account.
 

jj1314

Member
Joined
15 Feb 2011
Messages
89
It happens, especially with the composite brake blocks now fitted to Mk3 stock combined with poor rail head conditions that we have had in this wet weather.

Expect more of this sort of thing over the up and coming leaf fall season

Sorry to slightly change the topic, but might these new composite brakes be responsible for the slightly-strange odour not dissimilar to that of a burnt clutch plate I've noticed between Paddington and Didcot Parkway recently?
 

VP185

Member
Joined
13 Feb 2010
Messages
344
Mk3's are not fitted with brake blocks, they utilise brake discs and pads.

Brake fade is actually more a problem on disc braked trains especially at low speed than those fitted with blocks. The performance of disc braked trains varies greatly from train to train compared to those fitted with blocks.
 

irish_rail

Established Member
Joined
30 Oct 2013
Messages
3,876
Location
Plymouth
Brake blocks are a lot better than disc brakes in leaf fall/low adhesion as they clean the wheels. The low adhesion recently has been minimal and to be fair an over run at this time of year is seldom diagnosed to be because of poor adhesion. You get a lot more brake fade with brake blocks than disc brakes and as a driver take this into account.

WTF? "The low adheison recently has been minimal" Try talking to people who actually drive HSTs in the south west before coming out with bland statements like that. Since early summer (and especially the past month) adhesion has been very poor with the near constant rain.
As Rich Mclean points out, new brake blocks have worsened the problem as the wheels are no longer getting "roughed up" , giving less grip.
I have never known a summer like it for slippage (especially when under power), and am absolutely dreading the Autumn season.

Thoughts to the driver concerned in this incident......:|
 

HarleyDavidson

Established Member
Joined
23 Aug 2014
Messages
2,529
For me as a juice jockey, stopping doesn't appear to be an issue, it's the pulling away that causes issues, if you just sling a unit into full power, however the remedy is good old fashion hand notching if you're on a 455/456 or low power on a Desiro.
 

Rich McLean

Established Member
Joined
6 Feb 2012
Messages
1,685
EDIT:

Few things to clear up for clarity.

MK3 trailers are disk braked with pads

Power cars used to use cast iron break blocks. They now have composite break blocks which no longer rough up the powered wheels.This is where the issue is, and not from the Mk3 stock.

Sorry for any confusion
 
Last edited:

TEW

Established Member
Joined
16 May 2008
Messages
5,851
I was on the train last night. It did happen, and the correct parties were immediately informed by the train crew and the protocols followed.
 

VP185

Member
Joined
13 Feb 2010
Messages
344
EDIT:

Few things to clear up for clarity.

MK3 trailers are disk braked with pads

Power cars used to use cast iron break blocks. They now have composite break blocks which no longer rough up the powered wheels.This is where the issue is, and not from the Mk3 stock.

Sorry for any confusion

Power cars actually use a combination of both disc brakes and tread brakes (brake blocks), it's not shared 50/50 between the two though.
 

BestWestern

Established Member
Joined
6 Feb 2011
Messages
6,736
Sorry to slightly change the topic, but might these new composite brakes be responsible for the slightly-strange odour not dissimilar to that of a burnt clutch plate I've noticed between Paddington and Didcot Parkway recently?

That'll be the brakes, certainly, but it's nothing new. Under heavy braking HST trailers will always kick up a burning smell. Lets you know you've got a Driver who means business! <D
 

TDK

Established Member
Joined
19 Apr 2008
Messages
4,155
Location
Crewe
WTF? "The low adheison recently has been minimal" Try talking to people who actually drive HSTs in the south west before coming out with bland statements like that. Since early summer (and especially the past month) adhesion has been very poor with the near constant rain.
As Rich Mclean points out, new brake blocks have worsened the problem as the wheels are no longer getting "roughed up" , giving less grip.
I have never known a summer like it for slippage (especially when under power), and am absolutely dreading the Autumn season.

Thoughts to the driver concerned in this incident......:|

The statement is not bland it is fact maybe in the South West there has been adhesion problems but this is local, as I said it is very unusual that a train has an over run due to adhesion in August
--- old post above --- --- new post below ---
Mk3's are not fitted with brake blocks, they utilise brake discs and pads.

Brake fade is actually more a problem on disc braked trains especially at low speed than those fitted with blocks. The performance of disc braked trains varies greatly from train to train compared to those fitted with blocks.

Tread brake trains have more fade from high speed than disc brakes trains by far, low speed you are correct however I have not had noticeable brake fade from the disc brakes traction I drive at any speed.
 
Status
Not open for further replies.

Top