|
Post by Nortube on Oct 30, 2016 11:53:54 GMT
When I was at the school, most of the diagrams had to be drawn by hand into the exercise books provided. The instructor would draw them on the blackboard beforehand. This was in the days when the train equipment was based on 38 stock. Indeed, I think the main stock on all lines (except the Victoria line) at that time was based on offshoots of 38 stock (59, C60, 62 etc.), therefore, 38 stock teaching was a convenient way of standardising the train equipment teaching. Many of the principles (such as compressor and motor control were also very similar to those on the newer stock). Other stock used on the lines or depots that the crews would work from were covered as an extra day or two (depending on grade) locally during stock training.
The one exception to this was 73 stock on the Piccadilly line where an additional course was run after the Motorman passed the main course, to cover the then new equipment and major changes such as the Westcode brake, Round Train Circuit etc. The 73 stock was the first stock not to have train line air. Train line air was used to control the (fail safe) Westinghouse brake. Gradual loss of air was used for a service brake, a large loss of air initially applied an emergency / full brake. The large loss of train line air could be triggered by the operation of safety devices such as a tripcock or deadman, or an emergency handle. Loss of train line could be an indication of equipment such as a coupling engine not set correctly. Insufficient train line would, via the Control Governor, prevent the train motoring. The RTC effectively took over the role of the train line, by using an electrical circuit rather than air to do the same job of safety detection.
|
|
|
Post by Nortube on Oct 30, 2016 12:02:31 GMT
Dave1 I've just looked back through the forum and found the thread where I posted the MG, Compressors and EP diagrams from the site, together with notes for each diagram. If they're of any use: [ Click here ]
|
|
|
Post by dave1 on Oct 31, 2016 14:20:40 GMT
Dave1 I've just looked back through the forum and found the thread where I posted the MG, Compressors and EP diagrams from the site, together with notes for each diagram. If they're of any use: [ Click here ] Nortube Thanks I was going to pull them from your site.
|
|
|
Post by dave1 on Oct 31, 2016 14:23:02 GMT
When I was at the school, most of the diagrams had to be drawn by hand into the exercise books provided. The instructor would draw them on the blackboard beforehand. This was in the days when the train equipment was based on 38 stock. Indeed, I think the main stock on all lines (except the Victoria line) at that time was based on offshoots of 38 stock (59, C60, 62 etc.), therefore, 38 stock teaching was a convenient way of standardising the train equipment teaching. Many of the principles (such as compressor and motor control were also very similar to those on the newer stock). Other stock used on the lines or depots that the crews would work from were covered as an extra day or two (depending on grade) locally during stock training. The one exception to this was 73 stock on the Piccadilly line where an additional course was run after the Motorman passed the main course, to cover the then new equipment and major changes such as the Westcode brake, Round Train Circuit etc. The 73 stock was the first stock not to have train line air. Train line air was used to control the (fail safe) Westinghouse brake. Gradual loss of air was used for a service brake, a large loss of air initially applied an emergency / full brake. The large loss of train line air could be triggered by the operation of safety devices such as a tripcock or deadman, or an emergency handle. Loss of train line could be an indication of equipment such as a coupling engine not set correctly. Insufficient train line would, via the Control Governor, prevent the train motoring. The RTC effectively took over the role of the train line, by using an electrical circuit rather than air to do the same job of safety detection. Nortube So tripcocks and deadman handle were just switches on a 73 stock?
|
|
|
Post by Nortube on Oct 31, 2016 18:42:26 GMT
Basically, yes. I don't have the 73 stock handouts to hand (I'm not even sure where they are!). As I recall, the principle is that releasing the deadman opens a contact which breaks the RTC.
On a stock with train line air, if a train was tripped, the tripcock would be knocked back, opening the trip valve(?) and allowing train line to escape. Because it was necessary for the train line pressure to drop as quick as possible to apply the emergency westinghouse brake throughout the train, the hole in this and other safety valves (deadman, emergency handle etc.) was relatively large.
Again, if I recall correctly, I think that the operation of a tripcock on 73 stock (and later trains without train line air) initially works in the same way, but instead of train line air being released, air is released from below a piston, causing the piston to fall. The piston has contacts on the RTC circuit. Therefore, when the piston falls, the RTC is broken.
The above explanation for the deadman and tripcock operation is rather simplified and I'm sure that there is more equipment involved, but it shows the operation principle. Indeed, with most diagrams and note in the handouts, what is usually shown is a much simplified process - enough to show the basics of how the equipment operates, but doesn't contain the details that a fitter would need.
The same, as RT will tell you, that a track circuit has more than the one relay etc. that is shown in the school handout.
Sometimes handouts will give more detailed information. I remember a 72 stock control circuit (motors) handout showing far more contactors, relays etc. and extra wires / paths than would be shown on the normal motors handout. I'm sure many of the extras were for fail-safe operation, redundancy etc. I used to find it interesting following some of these - it was a bit like doing a jigsaw puzzle!
|
|
|
Post by railtechnician on Oct 31, 2016 23:30:46 GMT
Dave,
If you want to know about braking systems a good place to start is with a Westinghouse book. I have one which details Westinghouse brake equipment from the earliest days. Specifically it is a book on main line brake equipment but gives all the principles of Westinghouse brake systems. I have LU rolling stock course notes which did not come to me through the job but which I bought on Ebay a few years ago so I have a pretty good library on LU and mainline braking equipment albeit somewhat out of date now.
As for putting info online, I have a feeling that a technical website covering LU systems and equipment in detail would soon be forced to be taken down even though much of the information is in the public domain. The powers that be simply wouldn't want such a handy reference to be available to all and sundry. They know what can be found online but they also know that it has to be sought with a lot of searching because it is not 'collected' into a nice navigable website.
|
|
|
Post by dave1 on Nov 1, 2016 7:08:09 GMT
Dave, If you want to know about braking systems a good place to start is with a Westinghouse book. I have one which details Westinghouse brake equipment from the earliest days. Specifically it is a book on main line brake equipment but gives all the principles of Westinghouse brake systems. I have LU rolling stock course notes which did not come to me through the job but which I bought on Ebay a few years ago so I have a pretty good library on LU and mainline braking equipment albeit somewhat out of date now. As for putting info online, I have a feeling that a technical website covering LU systems and equipment in detail would soon be forced to be taken down even though much of the information is in the public domain. The powers that be simply wouldn't want such a handy reference to be available to all and sundry. They know what can be found online but they also know that it has to be sought with a lot of searching because it is not 'collected' into a nice navigable website. RT I have some BR information which helps in one respect but LU systems are quite different from what I understand although the basics would be very similar. There does not seem to be a lot of info on the web but what you have said makes good sense although NR put a lot of info but not signalling stuff. I did notice that someone requested track layouts for LU but the document had just the layout no point/signal numbers.
|
|
|
Post by dave1 on Nov 1, 2016 7:09:53 GMT
Basically, yes. I don't have the 73 stock handouts to hand (I'm not even sure where they are!). As I recall, the principle is that releasing the deadman opens a contact which breaks the RTC. On a stock with train line air, if a train was tripped, the tripcock would be knocked back, opening the trip valve(?) and allowing train line to escape. Because it was necessary for the train line pressure to drop as quick as possible to apply the emergency westinghouse brake throughout the train, the hole in this and other safety valves (deadman, emergency handle etc.) was relatively large. Again, if I recall correctly, I think that the operation of a tripcock on 73 stock (and later trains without train line air) initially works in the same way, but instead of train line air being released, air is released from below a piston, causing the piston to fall. The piston has contacts on the RTC circuit. Therefore, when the piston falls, the RTC is broken. The above explanation for the deadman and tripcock operation is rather simplified and I'm sure that there is more equipment involved, but it shows the operation principle. Indeed, with most diagrams and note in the handouts, what is usually shown is a much simplified process - enough to show the basics of how the equipment operates, but doesn't contain the details that a fitter would need. The same, as RT will tell you, that a track circuit has more than the one relay etc. that is shown in the school handout. Sometimes handouts will give more detailed information. I remember a 72 stock control circuit (motors) handout showing far more contactors, relays etc. and extra wires / paths than would be shown on the normal motors handout. I'm sure many of the extras were for fail-safe operation, redundancy etc. I used to find it interesting following some of these - it was a bit like doing a jigsaw puzzle! Nortube Thanks I suppose they have to keep the detail to a minimum for general training otherwise it would overload the person taking the course.
|
|
|
Post by Nortube on Nov 1, 2016 23:06:18 GMT
There have been various track diagrams provided internally and externally bu LU, not all to the same amount of detail, i.e. from a basic diagram showing the tracks and pointwork to more detailed scale diagrams which include all signals, blockjoints, point identification, overlaps and so in. The complexity of the diagrams depending on their intended use.
If the requested diagram originally had signal and point numbers but these were redacted when the document issued, then that just seems silly as it wouldn't make any security difference whether people had this information or not.
|
|
|
Post by Nortube on Nov 4, 2016 21:55:38 GMT
Where I mentioned the Train line air / Round Train Circuit equivalent in previous posts, it was rather generalised. There is a second circuit - the Safety Brake Circuit (usually referred to as the Safety Circuit)- that it tied in with this as well. Some of the safety equipment is on the RTC, some is on the Safety Circuit and some have connections on both.
The RTC is fed 52v DC at one end and the other end energises a relay. The energised relay holds a contact closed in the Safety Circuit. Breaking the RTC will de-energise the relay, causing the contacts to open on the safety circuit, thus applying the brake.
Whilst the cab emergency stop buttons are on the RTC, the main purpose of the RTC is generally detection, such as detecting that the rear TB is stowed, the rear Master Control Switch is in shutdown, middle and rear couplers are in the correct position, whether the rear tripcock is cut out, if the train has been rear tripped, if the train has been detected motoring whilst the shed leads are plugged in, etc. The RTC can be isolated if there is a fault on it.
The safety circuit is fed 52v DC at one end and the other end energises a coil which closes a contact on the feed to the brake control equipment. If the Safety Circuit is broken, the coil will de-energise and the contact open, cutting off the feed to the brake control circuit. The brakes will then apply.
The Safety Circuit cannot be cut out. However, it is duplicated into circuit A and circuit B. The default position is for Safety Circuit A to be used. If there is a fault with this circuit, then circuit B can be switched in instead.
The safety equipment that is on the Safety Circuit includes the Deadman, Front tripcock, RTC and Passenger alarm buttons / handles circuitry.
Note - the above is a generalisation and may vary according to stock.
|
|
|
Post by dave1 on Nov 6, 2016 11:53:09 GMT
Where I mentioned the Train line air / Round Train Circuit equivalent in previous posts, it was rather generalised. There is a second circuit - the Safety Brake Circuit (usually referred to as the Safety Circuit)- that it tied in with this as well. Some of the safety equipment is on the RTC, some is on the Safety Circuit and some have connections on both. The RTC is fed 52v DC at one end and the other end energises a relay. The energised relay holds a contact closed in the Safety Circuit. Breaking the RTC will de-energise the relay, causing the contacts to open on the safety circuit, thus applying the brake. Whilst the cab emergency stop buttons are on the RTC, the main purpose of the RTC is generally detection, such as detecting that the rear TB is stowed, the rear Master Control Switch is in shutdown, middle and rear couplers are in the correct position, whether the rear tripcock is cut out, if the train has been rear tripped, if the train has been detected motoring whilst the shed leads are plugged in, etc. The RTC can be isolated if there is a fault on it. The safety circuit is fed 52v DC at one end and the other end energises a coil which closes a contact on the feed to the brake control equipment. If the Safety Circuit is broken, the coil will de-energise and the contact open, cutting off the feed to the brake control circuit. The brakes will then apply. The Safety Circuit cannot be cut out. However, it is duplicated into circuit A and circuit B. The default position is for Safety Circuit A to be used. If there is a fault with this circuit, then circuit B can be switched in instead. The safety equipment that is on the Safety Circuit includes the Deadman, Front tripcock, RTC and Passenger alarm buttons / handles circuitry. Note - the above is a generalisation and may vary according to stock. I have followed the circuits and although the diagram is a simplified one I am beginning to understand much better than before so thanks for that. I see a number of fuses and all the problems that can be caused as a result in anyone of them blowing.
|
|