CaergwrleKen
Member
There has been a failure every day this week again and remember that only 2 230s are out a day, a 197 is regular every day on the long all day and night working first and last trains. It is as bad as ever all the usual excuses
That's shocking. Surprised network rail aren't getting them off the networkAnd last night (23rd) too.
Not actually seen any excuses or actions! Lucky Wrexham FC are away this weekend. Trains full of fans getting stuck is not a pretty thoughtThere has been a failure every day this week again and remember that only 2 230s are out a day, a 197 is regular every day on the long all day and night working first and last trains. It is as bad as ever all the usual excuses
'They' are not 'letting' this happen, what is happening is that the brake blocks are somehow picking up metal, being torn to shreds and then scoring the wheels at an alarming rate. This in turn has led to a sudden shortage of brake blocks (TfW are even having to borrow blocks from GWR) and a sudden increase in tyre turning, with all the disruption that brings having to send the units to Crewe (the nearest wheel lathe). The same appears to be happening, but to a lesser degree, with the 484 units on the Island Line. It seems to be linked to the Track Gel Applicators (TGAs) being switched on, and / or a spell of wet weather. Challenging conversations are being had with the brake block supplier and with Network Rail, because something weird is going on. It's such a shame that this is happening now, when in other respects things seemed to be improving.Another unit taken out of action last night due to brake blocks again. What's going on, why are they letting this happen on a daily basis?
Thank you, as always, for a helpful insight into what is happening. Always appreciated.'They' are not 'letting' this happen, what is happening is that the brake blocks are somehow picking up metal, being torn to shreds and then scoring the wheels at an alarming rate. This in turn has led to a sudden shortage of brake blocks (TfW are even having to borrow blocks from GWR) and a sudden increase in tyre turning, with all the disruption that brings having to send the units to Crewe (the nearest wheel lathe). The same appears to be happening, but to a lesser degree, with the 484 units on the Island Line. It seems to be linked to the Track Gel Applicators (TGAs) being switched on, and / or a spell of wet weather. Challenging conversations are being had with the brake block supplier and with Network Rail, because something weird is going on. It's such a shame that this is happening now, when in other respects things seemed to be improving.
This is very interesting thanks and it does throw light onto the matter. I suppose my statement should have been "why are they still in service until they solve the problem?"'They' are not 'letting' this happen, what is happening is that the brake blocks are somehow picking up metal, being torn to shreds and then scoring the wheels at an alarming rate. This in turn has led to a sudden shortage of brake blocks (TfW are even having to borrow blocks from GWR) and a sudden increase in tyre turning, with all the disruption that brings having to send the units to Crewe (the nearest wheel lathe). The same appears to be happening, but to a lesser degree, with the 484 units on the Island Line. It seems to be linked to the Track Gel Applicators (TGAs) being switched on, and / or a spell of wet weather. Challenging conversations are being had with the brake block supplier and with Network Rail, because something weird is going on. It's such a shame that this is happening now, when in other respects things seemed to be improving.
D Stock originally didn’t have lubesticks when new and relied upon trackside greasers. These were a much later modification.Was the D78 Stock (and in particular it's barking system) designed to work with trackside traction gel applicators? As far as I am aware, LU still operate overnight Sandite trains on the District Line during periods of low adhesion.
They are only kept in service until an inspection reveals damage to brake blocks and wheels sufficient enough to withdraw the units from service. I believe at the moment, because of the problems described, wheels and blocks are being inspected every day; this is not normal; normally you only need to visually inspect them every few thousand miles (depends on the fleet type). Obviously once the damage is bad enough, the blocks have to be scrapped, replaced with a new set, and similarly if the damage to the wheels is above a certain threshold, the units have to go to Crewe for tyre turning which gets rid of the damaged metal, and then you put them back into traffic until it happens again.This is very interesting thanks and it does throw light onto the matter. I suppose my statement should have been "why are they still in service until they solve the problem?"
That's interesting what you say about Sandite containing steel particles to ensure track circuit continuity; I didn't know that. Equally I cannot say for certain whether the particular Traction Gel employed on the Wrexham - Bidston line contains such particles; from what I can gather there are different types of Traction Gel. I will pass that on for consideration by the Engineers at Birkenhead! What's weird is that 'normal' greasers, which apply only grease (without sand in) to the gauge corner rather than to the middle of the tread (as is the case with TGAs), have also, in previous years, seemed to cause an 'uptick' in the damage being seen, so this is not a new phenomenon. Ditto for wet weather. And as I've said, this damage is happening on the Island Line where they don't have TGAs. So I don't think TGAs can be held totally to blame. All-in-all it seems that the brake blocks, for whatever reason, which are made from a composite material, just don't seem to be able to cope with contamination very well. The damage mechanism is probably something very similar to what you describe for road bikes with rim brakes in wet weather. The mystery is what exactly is being embedded in the blocks which is hard enough to cause scoring to the wheels. I guess that could be either metal particles or silica itself (which is generally harder than most steels). Note, just for clarity, that the 230 retains the same brake system as the D78; they are 'traditional' tread brakes (i.e. 'pusher' brakes) as opposed to disc/calipers of modern units. Normally tread brakes are inherently better at keeping the tread clean and therefore don't suffer so badly in slippery weather. Not so in this case, unfortunately!Was the D78 Stock (and in particular it's barking system) designed to work with trackside traction gel applicators? As far as I am aware, LU still operate overnight Sandite trains on the District Line during periods of low adhesion.
Applying Sandite (which contains steel particles to ensure track circuit continuity) to the rails means it can dry out before the first trains run over it the next morning. Applying wet traction gel directly to the wheel from a lineside applicator would allow to either be flung off into the brake blocks (depending on how fast the train is going) or wiped off on the next brake application. The steel and grit particles could then get embedded in the surface of the block and act like emery cloth on the tyre each time the brakes are subsequently applied.
If you ride a road bike with rim brakes in wet weather exactly the same thing happens - road grit gets splashed up onto the rim, then when you apply the brakes it gets embedded into the rubber brake blocks. This then acts as an abrasive that scores and prematurely wears the braking surface on the rim on each subsequent brake application. Before the arrival of road bike disc brakes, most serious road cyclists had a set of 'winter wheels', a cheaper set (usually alloy, as carbon rim brake tracks wear faster in these conditions) that were considered sacrificial.
I'm guessing because 197s have modern caliper brakes which act on brake discs on the 'cheek' of the wheels, whereas the 230s have old-fashioned tread brakes (still in quite common use on freight trains) where the brake blocks act on the wheel tread. It's the wheel tread that is getting 'contaminated' by traction gel, or grease, or just general muck, and it is the contamination which is thought to be initiating the damage to brake blocks and wheels on the 230s. Such contamination is less of a direct problem on disc-braked trains. As a suggestion, try Googling or putting into ChatGPT 'tread braking versus disc braking on trains', this should provide a reasonable explanation of the differences.Interesting turn of events. Why does it affect 230s and not 197s?
They do use dynamic braking most of the time. From what ive noticed sat in the back cab on them the brake guage needle moves up when the driver asks for brakes, it then releases back to 0 again once its realised dynamic brake is functioning, braking purely in dynamic mode. Once its a bit closer to stopping the air brakes kick back in to bring it to a stop. I think the air brake also intervenes if it detects wheelslip under dynamic braking.Do the brakes get used much? You'd think they would want to use dynamic braking as much as possible to get the most charge back into the battery!
Dynamic/rheostatic brake won’t operate on the middle trailer car.They do use dynamic braking most of the time. From what ive noticed sat in the back cab on them the brake guage needle moves up when the driver asks for brakes, it then releases back to 0 again once its realised dynamic brake is functioning, braking purely in dynamic mode. Once its a bit closer to stopping the air brakes kick back in to bring it to a stop. I think the air brake also intervenes if it detects wheelslip under dynamic braking.
Too right! I'm sure there should be a version of Murphy's Law for Rolling Stock Engineers, which would be something like, "Just when you're starting to think you've got on top of all the problems, something totally unexpected will come along and bite you in the backside"Going off on a tangent here but I remember a fair few years back at merseyrail the 507/8s had a spell where the shoes where becoming fused to the live rail causing flashovers and costly damage. That was found to be the substance the mpv was laying on the live rail. Just shows anything can happen
Yes that's pretty much exactly how they work. Regenerative (regen) braking (the motors turn into generators and the electrical energy goes back into the batteries) is 'blended' with friction braking at all times, to give the desired braking curve, but there tends to be more regen braking at higher speeds, with the friction braking coming in as the speed drops and (from memory) braking is entirely friction at something like 10mph down to 0mph. But it does depend on the braking effort demanded. In the case of an emergency stop I think it just goes straight into friction braking. And as you say, if the WSP needs to intervene then the regen braking gives up and the friction brake takes over entirely (because the WSP relies on quickly releasing / applying the air brakes to prevent wheels locking up).They do use dynamic braking most of the time. From what ive noticed sat in the back cab on them the brake guage needle moves up when the driver asks for brakes, it then releases back to 0 again once its realised dynamic brake is functioning, braking purely in dynamic mode. Once its a bit closer to stopping the air brakes kick back in to bring it to a stop. I think the air brake also intervenes if it detects wheelslip under dynamic braking.
Im happy to be corrected as I dont drive them or maintain them but this seems to be the case from watching the needle in the cab!
If this is the case, perhaps part of the cause could be the fact that the brake blocks arnt being used enough due to dynamic braking thus allows larger amounts of contamination to build up on both the brake blocks and the wheel surface?
At the same time, you need the dynamic brake there to keep the batteries charged!
Swings and roundabouts. It keeps the likes of us employed.Too right! I'm sure there should be a version of Murphy's Law for Rolling Stock Engineers, which would be something like, "Just when you're starting to think you've got on top of all the problems, something totally unexpected will come along and bite you in the backside"![]()
As mentioned in @Dstock7080 's reply, it seems the D78 Stock's brake system was not designed to cope with Sandite/Traction Gel contamination as it is not used on the District Line. They did originally use trackside greasers to reduce flange squeal when first introduced, but were subsequently modified to use Lubesticks, which apply a dry lubricant to the flanges via a spring-loaded applicator attached to each bogie (presumably the modiifcation was made because LU experienced the same issues with grease contaminating the brake blocks).That's interesting what you say about Sandite containing steel particles to ensure track circuit continuity; I didn't know that. Equally I cannot say for certain whether the particular Traction Gel employed on the Wrexham - Bidston line contains such particles; from what I can gather there are different types of Traction Gel. I will pass that on for consideration by the Engineers at Birkenhead! What's weird is that 'normal' greasers, which apply only grease (without sand in) to the gauge corner rather than to the middle of the tread (as is the case with TGAs), have also, in previous years, seemed to cause an 'uptick' in the damage being seen, so this is not a new phenomenon. Ditto for wet weather. And as I've said, this damage is happening on the Island Line where they don't have TGAs. So I don't think TGAs can be held totally to blame. All-in-all it seems that the brake blocks, for whatever reason, which are made from a composite material, just don't seem to be able to cope with contamination very well.
Looks like its one a day at the momentHow many 230s have they got in use at the moment each day?
All eyes on gwr who have just got a fast charge system. Bet TFW are keen to try thisOn various websites, when Vivarail first commenced their project, one thing noted at that time in postings made by "Shooter afficionados" was the constant use of the word "innovation".
With hindsight it turns out that one of the pitfalls of the Class 230s is how ’niche’ their use cases ended up being. Be that LNWR, TfW, Island Line. I believe that this has been alluded to previously.On various websites, when Vivarail first commenced their project, one thing noted at that time in postings made by "Shooter afficionados" was the constant use of the word "innovation".
Just got? It’s been in place and heavily tested pretty successfully for just under two years now, so the fact that it’s only just been put into passenger service is fairly inconsequential when it comes to the industry understanding what is possible.All eyes on gwr who have just got a fast charge system. Bet TFW are keen to try this
Not sure why you need to split hairs, I of course am talking about it just going into passenger service for the first time 31/01.Just got? It’s been in place and heavily tested pretty successfully for just under two years now, so the fact that it’s only just been put into passenger service is fairly inconsequential when it comes to the industry understanding what is possible.
There would however be challenges introducing it on the Borderlands route, most notably the dwell times needed which would be much greater than are currently available.