Point motor force?

[truckman060473]

Was just wondering how much power a point motor has? For example if a trespasser were to step into the blades as they change would it just trap his foot leaving him in a lot of trouble or would it crush his foot completely?

 

[EM2]

It would crush it.
Pretty much the first thing you are told when you start work on S&T, is that you never, ever reach between a stock rail and a switch blade.
The only caveat against that is if you have wedged the switch open (normally with the head of a hammer).

 

[ralphchadkirk]

Crush or taken off most probably. In short, it is not a bright idea to stick any extremity of your body in the way of point blades.

 

[Old Timer]

Its not that simple.

There are various sets of points and there are different forces applied to the switch rails.

The forces are not so great as to cause the switch rail to bend.

Air points will definitely cause a breakage of bones in the foot, and will retain this pressure until returned to the other position or disconnected.

Clamp locks and HW series / M series will drive but the motor will stop running after a specified period to avoid burning out if the points do not detect. There is a high risk of foot injury.

In all circumstances it is unlikely the foot can be released until the switch is return to the opposite position or moved away sufficiently to leave room for the foot to be extracted. Those wearing ordinary shoes/trainers are likely to receive serious crush injuries, whilst those wearing boots with steel midsoles will suffering somewhat lesser of an injury.

Certainly it is not something to be recommended.

 

[DaveNewcastle]

Is the traditional wooden scotch strong enough to resist the motor's geared movement (or pneumatic pressure where applicable) on all current point blades?

 

[Old Timer]

Is the traditional wooden scotch strong enough to resist the motor's geared movement (or pneumatic pressure where applicable) on all current point blades?

Definitely.

Anything not solid or structurally sound will be crushed, small stones tin cans bottles, etc, etc

Electric and hydraulic point motors are designed to motor for a period of time before the motor cuts out. This is to protect the equipment.

The pressure applied is sufficient to overcome the weight of the switch blades plus the operation of the backdrives.

Until the motor cutout operates, the motor will run and pressure will be applied to motor the points to the position required.

A foot would be crushed to the point where the blade can no longer move. A steel midsole in the right position will resist the closure of the blade, but not if the foot is twisted.

 

[NightatLaira]

So is a patch of heavily re-frozen snow (say at minus 6) sufficient enough to stop a point from working if it were laid longitudinally over several meters between the switch blades of a high-speed point? You always hear of frozen points in the winter..


One of the other things I've noted recently is the speed of the change of the points at Y221(North) on the platform 3/4 section of York controlling the Scarborough branch. You can see this point operating very easily between platforms 3 and 4 at York and in the old days it used to mozey across quite slowly with a whining noise taking maybe 1.5seconds to go from ahead to divert, now it clicks across with quite some force in ~0.2secs! Is this some sort of new motor?

 

[ChrisCooper]

So is a patch of heavily re-frozen snow (say at minus 6) sufficient enough to stop a point from working if it were laid longitudinally over several meters between the switch blades of a high-speed point? You always hear of frozen points in the winter..


One of the other things I've noted recently is the speed of the change of the points at Y221(North) on the platform 3/4 section of York controlling the Scarborough branch. You can see this point operating very easily between platforms 3 and 4 at York and in the old days it used to mozey across quite slowly with a whining noise taking maybe 1.5seconds to go from ahead to divert, now it clicks across with quite some force in ~0.2secs! Is this some sort of new motor?

Snow can quite easily stop points moving correctly. Even a fairly small amount between the switch blade and the stock rail can prevent proper detection, afterall the switch blade has to be tight to the stock rail or else a thin flange could end up going the wrong side and lead to a derailment. That's what point heaters are for, to melt snow and prevent problems, but sometimes it does still occur.

What about manual points? Is the leverage enough that a signaller of normal strength could crush someone's foot?

When it comes to finger's of cource, it doesn't take much to crush them. I wouldn't want to get my fingers anywhere never even some sprung or weighted narrow gauge points. Sprung ones especially are nasty, they return with a right crack after being trailed though. I'm always wary around tram points too, even though they are often in totally public places (such as on roads). Even the old manually operated ones I bet you can get enough leverage off the point iron to break someone's fingers. I do wonder due to the idiot proof world we live in if there is some safety built into powered tram points to prevent injury from someone stupid enough to put part of their body in them?

 

[KingboyD]

Has anyone's foot or other extremity ever been caught in a set of points?

 

[Old Timer]

So is a patch of heavily re-frozen snow (say at minus 6) sufficient enough to stop a point from working if it were laid longitudinally over several meters between the switch blades of a high-speed point? You always hear of frozen points in the winter..


One of the other things I've noted recently is the speed of the change of the points at Y221(North) on the platform 3/4 section of York controlling the Scarborough branch. You can see this point operating very easily between platforms 3 and 4 at York and in the old days it used to mozey across quite slowly with a whining noise taking maybe 1.5seconds to go from ahead to divert, now it clicks across with quite some force in ~0.2secs! Is this some sort of new motor?

A lot of it was to do with the grease thickening up, and obviously metal contracts so fine detection can be lost.

As far as snow goes, when crushed it turns to ice and that is sufficent to prevent the points going into detection.

Th epoints you refer to sound as if the were HW2000 but without a photo of the motor it is not easily possible to say what now operates them.

 

[Get-Pulled-Off]

So is a patch of heavily re-frozen snow (say at minus 6) sufficient enough to stop a point from working if it were laid longitudinally over several meters between the switch blades of a high-speed point? You always hear of frozen points in the winter..

As said, most points have heaters which in theory should not be overwhelmed until a vast amount of snow (the like of which not normally seen in England, but possible in Scotland perhaps) it's nearly always when the point heaters have failed that detection can't be obtained. De-icing them is a skill as well. If no de-icing equipment is to hand I've known some of our more industrious MOMs urinating on them. Seriously! Hot water alone freezes too quickly and makes matters worse.

Some points are not fitted with point heaters but these are usually on infrequently used ones. The normal practice for winter working is to abandon all loops, goods lines and non essential crossovers to minimise the movement of points.

Talking of jamming points, I could never understand why the Rule Book states if a junction is encounted when going to lay emergency protection you should lay 3 dets then head off in the direction you believe a train is more likely to appear from. Surely everyone would take the more pragmatic option of placing three dets and then jamming the points in whichever position they are set for using anything to hand and then heading off in the route the points are set for?

 

[The Informer]

Now this is scary......

At 9 elms recently, staff were working on a set of points when suddenly the points moved over trapping a member of staffs foot between the backdrive crank and rodding. One of the lookouts in the group tried to get the points reversed but panic and confusion took over! As the train was seen approaching a lookout started waving his red flag violently in hope that the driver would be able to stop in time.

The train came to a halt 5 chain (110y) away!

 

[455driver]

Talking of jamming points, I could never understand why the Rule Book states if a junction is encounted when going to lay emergency protection you should lay 3 dets then head off in the direction you believe a train is more likely to appear from. Surely everyone would take the more pragmatic option of placing three dets and then jamming the points in whichever position they are set for using anything to hand and then heading off in the route the points are set for?

Because train-crew are not trained in scotching points!
Now if something was to fall into the points jamming them?

Its the same with laying dets before entering a tunnel, when you then enter the tunnel, if you see a train approaching you are only supposed to show a red lamp (or flag) to the driver and not lay dets in tunnels, I know what I would do (and it would make a loud bang ) but if it was written into the rule book the union solicitors would have a field day.

Common sense comes into play with these things.

 

[Get-Pulled-Off]

I'm sure you meant it tongue in cheek but you can do pretty much anything provided it is to prevent loss of life or serious injury and not get critisised. But it doesn't take a bit of paper to know if you jam something in between the moving blades they ain't going to move anywhere!!

 

[SteveP29]

Has anyone's foot or other extremity ever been caught in a set of points?

I remember Doctor Who (played by Tom Baker at the time) when I was a kid getting his trapped between the rail and the point with a train heading towards him, I don't know how he escaped, but he obviously did as he lived to fight the cybermen again

 

[TomBoyRacer]

I remember Doctor Who (played by Tom Baker at the time) when I was a kid getting his trapped between the rail and the point with a train heading towards him, I don't know how he escaped, but he obviously did as he lived to fight the cybermen again

The Deadly Assassin -
One of the best episodes they ever did. 'You're finished Doctor!!!'

The train just dissapears and he's no longer trapped, as it's all in his mind.

http://www.youtube.com/watch?v=8YCCu5dEZ-0&feature=related

 

[Vinnie Fox]

Now this is scary......

At 9 elms recently, staff were working on a set of points when suddenly the points moved over trapping a member of staffs foot between the backdrive crank and rodding. One of the lookouts in the group tried to get the points reversed but panic and confusion took over! As the train was seen approaching a lookout started waving his red flag violently in hope that the driver would be able to stop in time.

The train came to a halt 5 chain (110y) away!

I saw that in the monthly safety briefing.

Cut a long story short, nine years or so ago we had a new starter kept putting his hand in EPs when cleaning them, I told him several times not to, he looked at me as if I was giving it the old sweat's act, soon after that they went over, thankfully he'd heeded my warning and his fingers weren't in there but the blood drained from his face as it dawned on him what would have happened if he hadn't listened.

On reflection I should have got the Signaller to swing them across and back before we started work just to let the lad know what he was dealing with.

 

[Trog]

Talking of jamming points, I could never understand why the Rule Book states if a junction is encounted when going to lay emergency protection you should lay 3 dets then head off in the direction you believe a train is more likely to appear from. Surely everyone would take the more pragmatic option of placing three dets and then jamming the points in whichever position they are set for using anything to hand and then heading off in the route the points are set for?

I was once at an S&T run training school when this question came up. The S&T trainer was horrified at the number of ways half a dozen P-Way blokes could come up with to sabotage the S&T's kit so the points could not be moved.

 

[AlexS]

Certainly I've known people get fingers trapped in switch blades before.

As a signalman and fair weather S&T installer (not allowed to be a technician and I don't think I'd want to be, far too techy for me!!) on a preserved line (we have rather excellent vintage HB point machines in use in a few locations) the first thing you're told is not to put anything in the blades unless you've isolated the motors - even if the S&T technician says they're taking the motors off power I always collar the buggers up to be on the safe side, do not want to unwittingly do a mate some damage!

 

[Jonny]

This reminds me of a primary school visit from BTP - almost 25 years ago now - where the really good-at-football kid got his foot stuck in a point while trespassing and never played again.

 

[WL113]

EP machines certainly go over with terrific force and not much warning. BANG-SSSSS and they are locked, certainly no place to put any part of the body. With HW points the motor can be heard running just before the switches start to move. I have never been near Clamp lock points when they move so don't know much about those.

 

[Old Timer]

EP machines certainly go over with terrific force and not much warning. BANG-SSSSS and they are locked, certainly no place to put any part of the body. With HW points the motor can be heard running just before the switches start to move. I have never been near Clamp lock points when they move so don't know much about those.

WE used to kill rats in the blades of EP motors at Rugby !

 

[WL113]

Not nice! I did hear of someone exploding a detonator in a set of air points once. Naughty!