NIR Hunslet prototypical behaviour

[murphaph]

Does anyone know if the radiator fan on the Hunslets ran independently of the prime mover? I would have expected it to be able to run on after the prime mover had switched off to prevent overheating after shutdown. Did the fan operate at varying speeds? How slow did it go?

What would the normal order of operations have been for the lights?

Driver enters cab, switches on cab lights (assuming it's dark), then the marker lights and then the headlight?

If running light engine would the red marker lights come on simultaneously with the white ones or come on a moment later after the white marker lights?

When a driver changed ends, did he have to shut down the loco to take his key with him to the other end, or was it possible to change ends without shutting down the prime mover?

I'm tinkering with the sound settings on my Loksound at the minute, hence the questions. Appreciate any help

[Signal Post]

They are very good questions, I don't know the answer to any of them, however many of them would also be applicable to other diesels of the period such as the CIE A and C classes and the 141/181 and 071s.

Just thinking about your question re the marker lights has set me thinking.....I was fortunate enough to get a cab ride in the baby GM B142 at Whitehead during one of their Diesel Days earlier this year (very much recommend same to any forum members with an interest in such matters) and one of the photos that I took was of the control panel for lights etc as shown below

 

 

The Marker Lights switches are labelled as "White", "Red" and "Shunt" and the "Cab" light switches and Headlight switch (Bright/Off/Dim) are also visible on the panel. As far as I remember this was the No. 1 cab end.

From the above it would seem that the markers would come on more or less simultaneously (assuming he turned both switches on for light engine running together).

As regards shutting down the prime mover during a change of ends I would suspect not, I have heard that it could be quite difficult to get them started again to the extent that they (the A class) would be left running all night in Tralee (the environmentalists among us are probably reaching for their smelling salts at this stage...). I don't know if this was just a difficulty in starting from cold or a general reluctance to start.

Hopefully some of the more knowledgeable folks will be along with more definitive answers.....

[GSR 800]

1 hour ago, Signal Post said:

They are very good questions, I don't know the answer to any of them, however many of them would also be applicable to other diesels of the period such as the CIE A and C classes and the 141/181 and 071s.

Just thinking about your question re the marker lights has set me thinking.....I was fortunate enough to get a cab ride in the baby GM B142 at Whitehead during one of their Diesel Days earlier this year (very much recommend same to any forum members with an interest in such matters) and one of the photos that I took was of the control panel for lights etc as shown below

 

 

The Marker Lights switches are labelled as "White", "Red" and "Shunt" and the "Cab" light switches and Headlight switch (Bright/Off/Dim) are also visible on the panel. As far as I remember this was the No. 1 cab end.

From the above it would seem that the markers would come on more or less simultaneously (assuming he turned both switches on for light engine running together).

As regards shutting down the prime mover during a change of ends I would suspect not, I have heard that it could be quite difficult to get them started again to the extent that they (the A class) would be left running all night in Tralee (the environmentalists among us are probably reaching for their smelling salts at this stage...). I don't know if this was just a difficulty in starting from cold or a general reluctance to start.

Hopefully some of the more knowledgeable folks will be along with more definitive answers.....

Can't speak all that much for the A class other than knowing the one on standby at Limerick Junction was kept on for fear it wouldn't restart!

Trying to cold start a loco during the winter can be a complete nightmare. Best to at least have it run for a few hours a day so its never completely cold.

 

[murphaph]

Looking at that control panel (thanks for uploading!) and assuming there's a matching panel in the other cab, then the marker lights are set in cab 1 or end 1 and cab 2 for end 2. There is only one switch for each colour. It's presumably possible to have (albeit incorrectly) all the white and red marker lights on on both ends simultaneously. The driver needs to manually check that they have switched the unneeded ones off, as well as switching the needed ones on. It's not a case of "turn on end 1 white lights and end 2 white lights will extinguish". There is no remote control of the marker lights at the other end. The driver needs to walk to the control panel at the other end to set the marker lights at that end. That's what I would assume looking at the control panel pictured. Anyone know any better?

Edit: Was the Baby GM running light engine at the open day?

Edited June 28 by murphaph

[mfjoc]

The GM engine had a tendency to dump its coolant if it was shut down and let go cold. After the first oil crisis boilers were fitted to keep the engine warm but these were not reliable and drivers tended to leave the engine idling overnight rather than risk a restart.

[BSGSV]

19 hours ago, murphaph said:

Driver enters cab, switches on cab lights (assuming it's dark), then the marker lights and then the headlight?

If running light engine would the red marker lights come on simultaneously with the white ones or come on a moment later after the white marker lights?

When a driver changed ends, did he have to shut down the loco to take his key with him to the other end, or was it possible to change ends without shutting down the prime mover?

Based on my observations/activities over thirty+ years, I would comment as follows. Others can differ!

The driver will have a torch at night, and may just rely on it and ambient light until they are sitting down, to maintain their night vision. Or could stick on a cab light, perhaps for a while to read paperwork etc. Each to their own! Marker lights will be set for that end for the direction of travel - two whites for forward, red(or reds, could be one or two depending on class/period) if this cab is the rear, one white/one red each end if shunting. The full headlight won't tend to be used where there is good light - stations, yards etc., or when meeting an oncoming train in the opposite direction - you don't want to blind your colleague - so you'll dim the headlight or turn it off. Like all humans, drivers can forget or mess up any or all of these at times!

As you guessed, the marker lights lights each end are set independantly, and stay that way until altered in the relevant cab.

Changing ends requires the engine in idle, brakes applied and no direction set, but the engine isn't shut down.

I am not familiar with the cooling system on the Hunslet, but different classes have different set ups for the fans. I would guess the Hunslets would have a fan controlled by thermostat on the cooling water with perhaps two/three different speeds (aside from off). Cooling tater temperature will vary depending on load, road, ambient temperature, how well the radiators is working (i.e. are the fins clogged with dirt/cement dust like 102's were when it was last shunting at Adelaide). 

3 hours ago, mfjoc said:

The GM engine had a tendency to dump its coolant if it was shut down and let go cold.

The engine itself was fine. The cooling system has Marmon couplings in the main pipes from engine to header tank, oil cooler, radiator and such, and if these weren't right, could drip badly. I was told a story (I hope apocrophal) that the Marmons leaked so freely that the water was coming out faster than they could fill the system. The cooling water boiler was to keep temperatures up, the engine warm, everything expanded and avoid frost damage. Ethelene Glycol tends to be added to the cooling water, certainly these days, but was not always used. Antifreeze will not, however, help a cold battery crank an engine - starting stuff in the cold can often be a pain.

[murphaph]

Excellent information. The lighting on a lot of our models tends to flip over instantly when the direction is changed but in reality it would have taken at least the time the driver would have needed to walk to the other cab. Does anyone know if the rad fan was driven mechanically or (also?) electrically? I am assuming it would have been able to stay running or even start running after engine shutdown after a hard run?

When changing ends in a Hunslet, did the driver walk through the engine compartment or externally?

[BSGSV]

17 hours ago, murphaph said:

Excellent information. The lighting on a lot of our models tends to flip over instantly when the direction is changed but in reality it would have taken at least the time the driver would have needed to walk to the other cab. Does anyone know if the rad fan was driven mechanically or (also?) electrically? I am assuming it would have been able to stay running or even start running after engine shutdown after a hard run?

When changing ends in a Hunslet, did the driver walk through the engine compartment or externally?

It sounds like the model has scaled down the time it takes for the driver to walk through from end to end too! On A's, C's, Hunslets the driver would have walked through the loco. You get wet changing ends on a GM.

A and C class fans and (I think) the Hunslet, had electric motors for the fans, driven by current from the Auxiliary generator. The aux gen doesn't produce if the engine isn't running. Older locos aren't as sophisticated as your car! Fans have ball bearings and can run down for a long time after taking power off.  

 

[Mol_PMB]

26 minutes ago, BSGSV said:

It sounds like the model has scaled down the time it takes for the driver to walk through from end to end too! On A's, C's, Hunslets the driver would have walked through the loco. You get wet changing ends on a GM.

A and C class fans and (I think) the Hunslet, had electric motors for the fans, driven by current from the Auxiliary generator. The aux gen doesn't produce if the engine isn't running. Older locos aren't as sophisticated as your car! Fans have ball bearings and can run down for a long time after taking power off.  

 

From personal experience (of walking through a working XA class), you would have got filthy walking through a Crossley-engined A class! I expect some drivers would gone via the trackside.

[murphaph]

Interesting discussion. I ask because the Class 20 sound project I am using for my Hunslet has cab door opening and closing sounds. If the driver stays inside the loco, there's no need to play those when changing ends.

Has anyone got a video of the fan spinning up and down under an IRM decoder? My project just starts the fan quite abrubtly. I wonder what an original decoder has it do.