What is the equivalent in Britain to what we call “restricted speed” ? This is when a train movement authority is very diminished, requiring the engineer’s [driver’s] judgement of speed without knowing what is ahead on the line. Very, very slow in blind curves or rain and fog. This is used alot in the US.
Restricting speed is one of the reasons US passenger trains crawl along at ultra slow speeds approaching stations, through many sidings and much “padding” is required on passenger train scheduals because the train speed is up to the engineer and weather and night/day conditions.
I noticed when in England many trains approach stations at high speed and brake last minute, and generaly don’t have long stretches of exsessively slow crawling like in the US.
Still there must be some equivelency to restricted speed in the UK.
While I don’t know what the equivalent to “restricted speed” is, I do know it will be rarely used except within actual marshalling or storage yards. All mainline running tracks, and especially in the vicinity of stations, are fully protected by signals so the only limit on speed is the track geometry (curves and turnouts). The British, and western Europeans, would consider the need to go slowly because of uncertainty about conditions ahead on the line a very primitive and unsafe operating procedure. At busy stations traffic density requires that trains pass through and clear the approaches quickly to release the plant for the next train.
Even on branch lines where signals may not be apparent, the driver has the assurance of sole occupation either by a physical token or the modern RETB system. (I think that’s the right acronym.)
To add to the previous comment. Signalling has two possible purposes, though they may be closely linked. The first is to ensure there is only one train on a particular piece of track, the second is to regulate the speed at which trains travel. British signalling has almost exclusively looked at the first.
This was done by a system of “blocks” and it was in all normal circumstances forbidden to have more than one train in each block. This was done in the days of mechanical signalling by fixed boards (semaphore signals) that were only cleared when the signalman had received a message from the block ahead (usually the next signal box) that the block was in fact empty. Block signalling though mechanical means (ie signals physically moved through human muscle power) still exists on on considerable number of lines, some of which such as Barnetby in Lincolnshire and Shrewsbury in Shropshire, being busy with near double figure movements per hour. The boxes (towers in American parlance) that control these layouts are physically big and are usually near or very near to stations. All boxes have been interlocked since the late 19th century, which means that it is not possible to set signals for a particular route unless a) the route is clear, and b) the points are correctly sert.
The block principle applies just as much to colour light signals. But in this case track circuits play a vital role. Track circuits are created by sending an electrical current down an insulated section of one of the rails. When a train goes along that line it creates a short circuit. This is used both to show the signalman where the train is and to turn the preceeding signal to red. As the train moves further down a section of plain line the track circuits further down turn to red and the track circuits to the rear of the train ensure that when the train is out of the block the signal clears to a proceed aspect. In simple systems there are t
Thanks for the replies. I will consider restricting speed rare in Brtain.
In the US they have block signals on many lines too, but a second train may often enter a block without permission at restricted speed. ie a train may pass a red light block signal at resticted speed.
Restricted speed is over used in the US and makes passenger trains very slow and subject to weather coditions and engineers judgement.
But then my question would be, how in Britain would trains be able to couple together on the main line? Like a banking engine or when two trains are combined ? On a foggy day or in a blind curve, they must have some equivelency to “resticted speed” even if rarely used.
All modern British signalling uses the ‘absolute block’ system, whereby only one train is permitted within a section at any one time (subject to a very few specified exceptions). The rules whereby a train is permitted to pass a danger signal at reduced speed is ‘permissive block’ – this was outlawed in the UK for passenger lines in the Victorian era, and I doubt if there are any goods lines left with permissive signalling today.
Where routine coupling/uncoupling of trains occurs, this would take place either within a station or in a siding/yard clear of the main running lines, and would normally be controlled by shunting signals provided for the purpose. The only place where banking still occurs is at the Lickey Incline – the train stops in a loop clear of the running lines, and the banker then runs out from a short trailing siding and couples onto the rear. Combining DMU or EMUs into longer formations is quite common, but usually takes place in a station where the signalling allows such a move.
I’m not sure what the rules are about severely reduced visibility – I would assume that they are strictest for lines still controlled by semaphore signals and/or not equipped with AWS (basic cab signalling), but these tend to be lower speed lines anyway. On lines with AWS and power signalling I don’t think fog has much of an impa
It’s the paper version of British absolute block control. I am not sure anyone in Britain has used it for about 100 years, but it remains common in former British Empire railways such as India, Pakistan, and in the Middle East. Not to worry – I was just curious if you were familiar with it.
Like Cricketer I hadn’t come across the term ‘paper line clear’. From some Indian documents on the net it sounds like the old ‘telegraph and crossing order’ system widely used on single lines in the early days. I don’t think this has been used in the UK since the 1800s as most single lines went over to Tyer electric tablet operation or similar. I think the latter is still in use in a few places, but most single lines these days are operated as tokenless blocks, by RETB (Radio Electronic Token Block), or ‘one engine in steam’. The latest signalling arrangement for single lines is a European standard in-cab system called ERTMS.
What is the English practice when the signal system fails at either a single control point or on a number of control points along a line. Are trains moved or are the allowed to remain stopped until the signal system can be repaired? If they are permited to move, under what type of rules and at what speeds are they moved.
This is doubtless not up to date (I copied it from a 1962 accident report) but the famous ‘Rule 55’ set out the procedures to be followed when a train was stopped at a signal. Rule 55 was well known for the requirement that (where there was no track circuiting or signal post telephone) the fireman had to walk to the signalbox to sign the train register after making sure that the signalman had taken adequate steps to protect the stopped train. This was to prevent the signalman forgetting he had a train standing and then accepting another – a major cause of accidents over the years. Anyway, in relation to automatic signals remote from signalboxes the rule was as follows:
If a single signal has failed then trains stop and the driver uses the 'phone attached to the signal to request permission to proceed at restricted speed - basically line of sight.
Most main lines are signalled by centralised control centres. If one of those fails then everything tends to stop until it is sorted out with resulting huge delays.
The answer to an earlier question about coupling up additional units etc. is that the signal protecting somewhere lke a station platform will have an aspect that tells the driver that he can proceed but that the platform is already occupied - the old term was a calling on signal. This is very common in places where trains split and join and also at terminal stations where in quieter periods two short trains might use the same long platform.
Speed is controlled by general speed restrictions related to track geometry rather than the signals which generally just allow trains to run up to the permitted line speed. There are all sorts of complications such as flashing yellow signals to warn trains that they are set for a diverging route at the signal ahead and therefore need to slow down and approach control where a signal won’t clear unless the train has slowed down to a set speed.
I come to the conclusion that in Britain there is no real equivialant to “restricted speed” as known in the US (stopping in half the range of vision) I just noticed that railway wagons, both passenger and goods in Britain have no provision to even ride the point. Nowhere to hang on to and no windows at the end of many coaches even. So therefore their rules must be completely different. If nobody ever “rides the point” then …?
Obviously the job gets done, but with no headlights (traditionaly) and none riding the point when backing. Interesting.
Lots of people think that a railway is a railway is a railway. The worse the facts fit their preconception, the harder they whale on the square peg to make it fit the round hole they are just sure it will slide right into.
After you’ve been around this for awhile you realize that about the only thing you are sure about is that British and North American railways have the same gauge. More or less.
There is nothing in British Operating Rules for restricted speed as in the thread topic (although it does exist on the continent). However there are permissive working circumstances (two trains in the same block to couple in stations etc.) and this is controllable through the signalling system.
An example maybe on the approach to a station where a passenger train couples. The home signal which controls the entrance to the station line will have a subsidiary signal, when the coupling train has occupied the berth track circuit for the signal for an appropriate time the subsidiary signal will then “come off” - i.e. authority to come into the station. The speed of the train coming into the station is dependant on the drivers judgement.
Rule 55 has long since disappeared…! However where there is a signal failure of any description then “restricted speed” is enforced in terms of a caution. For example if there is a Track circuit failure then the signalman (or woman) will ask the first train to examine the line. That speed for examination is up to the person wangling the handle. However the driver will be advised to be able “to stop short of any obstruction” which implies a speed where the driver can be able to bring their train safely to a stand short of that obstruction…
In Brtitain, there is also a ‘Restricted Speed’ (excatly the same name) rule. Normally, and if memory doesn´t betrays me, it means that trains getting a signal indication to accomplish such restriction will not be allowed to run at more than 20 mph. This condition will normally be presented to the engineers by means of wayside signalling - wether coulour, semaphore or wayside speed boards. There is also an onboard cab signalling system called AWS, that in certain circumstances will force the engineer of a given train to accomplish such restriction.
In terms of the so calle crawling, normally signal blocks in Europe are not as long as the ones in the US, wich means that restricted speed zones might be smaller (also trains are smaller).
About trains getting to brake in the last moment, it’s a typical driving technique used in Europe, since most modern trains have quite powerfull braking systems allowing for such fast platform entrances. One can also see it as a way to minimise delays (less time for acomplishing one service stop), gain some little extra capacity (time consumed in stops and stopping procedures is optimised), and also to save energy, since oone only accomplishes one (strong) service brake appliance. There’s also another situation : In most of Europes’s main lines, track speed is normally pretty standartised, with speed restrictionns reduced to the minimum essential
No, there isn’t. There is no specific rule for restricted speed in the circumstances described at the top of the thread as we don’t allow for permissive working unless defined for locations in the Special Box Instructions or in emergencies under a senior managers authorisation. There is no specific signal to say this on any line in the UK network unless you discount LU or HS1. On the latter the TVM430 in cab signalling will work as a restricted speed as the blocks are computerised marker boards. I cannot comment on the Metro systems in the UK as I am not knowledgable in the field.
The 20MPH restriction is verbally passed from the signaller to the driver (engineer) for a specific range of circumstances (such as a track fault). This will be achieved either by radio (there are only a few locations fitted with box to cab radios) or, more commonly by stopping the train at a signal in rear and advising the driver from there. In 90% of circumstances drivers will be cautioned or asked to examine the line this occurs if you have a problem such as a Track Circuit failure. The speed which the train then travels is entirely up to the driver whilst they proceed over the affected section. Normally, especially if you are asking them to examine they will travel at a speed where they can be prepared to stop short of any obstruction…