Train driver 'freewheels' broken down train 13 MILES to London Euston after a power cut

[big all]

You can do the entire trip from a standing start at Knucklas to Knighton without taking power. There are a couple of drivers who when it's time to leave Knucklas merely release the brake, and don't touch the throttle.

Supposedly back in the 50s/60s when many services in Ireland were worked by AEC built railcars, they had a design feature where the dead man's handle had to be pushed down with one hand all of the time or else the brakes would kick in. However, if you put the reverser into neutral, it would disable the deadman's and given Ireland's generally flat topography, you could coast for miles and save your muscles!

the dead mans handle is a safety device to stop the train if the driver is incapacitated

did isolation happen well off course it never happend ------------
------------when the traction inspector was about
if it did he would cough until it was in direction off travel
dmmus only had forward and reverse in the uk
locos and emus on the southern where fitted around the mid to late 1980 with ssf[speed sensitive brake application ]to apply the brakes if in neutral around the 10mph mark to allow driver only operation without a secondman or guard

 

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I'm not quite sure I understand - neutral doesn't take the dogs fully out of connection to the transmission or something? Other than its a 4-speed mechanical transmission in which you can only coast in top gear I don't really fully understand the intricacies of it.

the reason you dont have neutral is you need the dogs to be positively in forward or reverse by air pistons because all the time you have any movement unless they are full home you have one part moving and one part stationary
if the dog [toothed gear/clutch] is stationery and meshes with the other moving half it can shatter or get damaged

 

[hexagon789]

the reason you dont have neutral is you need the dogs to be positively in forward or reverse by air pistons because all the time you have any movement unless they are full home you have one part moving and one part stationary
if the dog [toothed gear/clutch] is stationery and meshes with the other moving half it can shatter or get damaged

But presumably the dogs can be disengaged somehow at least when stationary?

 

[big all]

But presumably the dogs can be disengaged somehow at least when stationary?

from memory they could not with engines running you would be in forward or reverse
to haul a unit dead you had to isolate the engines and the use the fork to isolate the transmissions meaning the transmission was stationery so no danger off damage
when in practice you would couple the main res hose to give air to the transmission and horn on the unit use a fg1key[dmmu controler key ] place the reverser in forward to engage the dogs
and if you had to shunt into the sidings the other end you would reverse the reverser to stop the transmission possibly causing damage to a backwards turning engine

 

[Strat-tastic]

What are these dogs, of which you speak?

And what have they got to do with pencil sharpeners?

 

[hexagon789]

from memory they could not with engines running you would be in forward or reverse
to haul a unit dead you had to isolate the engines and the use the fork to isolate the transmissions meaning the transmission was stationery so no danger off damage
when in practice you would couple the main res hose to give air to the transmission and horn on the unit use a fg1key[dmmu controler key ] place the reverser in forward to engage the dogs
and if you had to shunt into the sidings the other end you would reverse the reverser to stop the transmission possibly causing damage to a backwards turning engine

There is something in what you say, but the excellent railcar website seems to suggest that there is a neutral unless I've understood it's page on the gearboxes wrongly.

 

[Jan]

What are these dogs, of which you speak?

This kind of dog.
Also watch this series of films if you have a little spare time:

 

[headshot119]

There is something in what you say, but the excellent railcar website seems to suggest that there is a neutral unless I've understood it's page on the gearboxes wrongly.

There is no neutral position on the reverser, only "F" for Forward and "R" for Reverse. The spoon (direction selector) is removable, and has to be in one of the two positions to mechanically unlock the rest of the gear controller.

The gear controller has five positions, "N" Neutral, 1, 2, 3, 4.

The DSD which is built into the throttle controller is active whenever the desk is live, irrespective of what position the gear controller is in. The only way to isolate it is to turn a handle under the desk, however that desk is only present in the motor cars, so it's extremely difficult to do if driving from a trailer

To isolate the transmission, the only way to do it is to use a fork to isolate each final drive (One per motor bogie)

 

[hexagon789]

There is no neutral position on the reverser, only "F" for Forward and "R" for Reverse. The spoon (direction selector) is removable, and has to be in one of the two positions to mechanically unlock the rest of the gear controller.

The gear controller has five positions, "N" Neutral, 1, 2, 3, 4.

The DSD which is built into the throttle controller is active whenever the desk is live, irrespective of what position the gear controller is in. The only way to isolate it is to turn a handle under the desk, however that desk is only present in the motor cars, so it's extremely difficult to do if driving from a trailer

To isolate the transmission, the only way to do it is to use a fork to isolate each final drive (One per motor bogie)

That's what I mean, Neutral on the gear selector. If that doesn't then isolate the transmission what does it actually do?

 

[chuff chuff]

That's what I mean, Neutral on the gear selector. If that doesn't then isolate the transmission what does it actually do?

It's like sitting at traffic lights in your car,pop on parking brake a put gear lever in wobbly ie neutral.

 

[hexagon789]

It's like sitting at traffic lights in your car,pop on parking brake a put gear lever in wobbly ie neutral.

I get that you have to be stationary in neutral, railcar notes otherwise the gear train is placed under stress and the Fluid Coupling rapidly overheats, but what does it actually do if it doesn't disengage the transmission.

Surely the engine would be free to rotate without being connected to the wheels for this, and surely that constitutes the transmission being disconnected?

I feel as though I'm not understanding something fully here.

 

[headshot119]

That's what I mean, Neutral on the gear selector. If that doesn't then isolate the transmission what does it actually do?

Ah my apologies I see what you are getting at now.

Neutral on the gear selector does disengage the engine from the input side of the gear box. However the dogs will still be engaged inside the final drive, and therefore the output side of the gearbox is still connected to the wheels. That is where the risk of damage comes from when hauling a unit dead, and why the dogs need to be manually disengaged.

 

[hexagon789]

Ah my apologies I see what you are getting at now.

Neutral on the gear selector does disengage the engine from the input side of the gear box. However the dogs will still be engaged inside the final drive, and therefore the output side of the gearbox is still connected to the wheels. That is where the risk of damage comes from when hauling a unit dead, and why the dogs need to be manually disengaged.

Thank you, I think we've both got a bit confused with what the other meant there!

I think I understand why you need to isolate now. The input and output sides aren't connected in neutral but each side is still connected to something.

 

[headshot119]

You've got it. It's funny, I've only ever needed to isolate the dogs on days where it's pouring with rain. It never happens when it's nice and sunny outside.

 

[Strat-tastic]

This kind of dog.
Also watch this series of films if you have a little spare time:

Thank you, that was interesting, although the video made no mention of them.