OTMR

I have a question long in my mind that predates OTMR but bat the same time may have some relevance to it.

OTMR would appear on the face of it to have more capacity than required for steam traction.

I would have thought that spare capacity might be used to monitor journal temperatures and to warn of impending problems so that appropriate action may be taken.

This is a serious query, I understand that extra cost may be involved but by the same token if damage is avoided damage expense would be saved.

This is perhaps a question Bob or someone in a similar position would be best placed to answer.

I have always thought that if a potential fault can be identified then it is better to be able to rectify the fault before it becomes serious or to be able to take appropriate action to avoid delays.

Hoping for a positive discussion.

Cheers Dave

 

Some years ago, I spent some time looking into the use of spare OTMR channels for recording additional parameters such as bearing temperatures, steam chest pressure etc but rapidly came to the conclusion that the existing OTMR design is not very flexible and that it would be much simpler and cheaper to install a separate commercial data recorder for this purpose. Indeed I came up with a system desgn with a built-in Bluetooth link which would allow the data to be monitored in realtime from the support coach. It included a GPS unit and as an optional extra it also included strain gauges in the engine-tender drawbar so that the drawbar tension and hence drawbar horsepower could also be monitored - in effect it measured nearly everything that a dynamometer car would measure in days gone by. However at the moment it is still just a paper design !

David

 

If it helps, I can assist with clearing up what may be a couple of preconceptions with how OTMRs are generally designed. Firstly, recording digital data is cheap and easy, recording analogue data is difficult. In other words, if you want to record if something is "on" or "off", then that's simple and cheap. If you want to record a variable value between "full on" and "full off" - an analogue value - then that is quite costly in terms of recorder capacity. Secondly, and perhaps most relevant to the question about journal temperatures, OTMRs do not provide real-time warnings to train crew. They record what happend for analysis later. So, one may be able to record that a journal has overheated, and if you spend enough, you may be able to produce a nice temperature graph to show the enquiry - but none of that helps to avoid the failure in the first place.
This is why certain modern trains have instrumented bearings (I THINK Class 390s have these) which will give a real-time warning to traincrew. At that point, you are into serious money.

Hope that helps?

 

Something similar to what is used in modern cars may be possible. Based on a CAN serial data bus and using low-cost sensors perhaps?

 

David

Nice to hear that someone had had similar ideas could be worth pursuing on a theoretical basis..

Simon

The reading of analogue data into digital is not that difficult we used to use an 8255 A/D board and using a pendulum and rheostat read the input and demonstrate the variations in voltage in real time as a sine wave on the crt of a computer.

This could be a project if enough like minded people worked together to keep the cost down.

Cheers Dave

 

Just curious - where is the actual business requirement?

In other words, how many mainline steam excursions have failed in the recent past in a fashion whereby some prior warning sign to the crew may have allowed them to prevent a failure, or at least terminate the train in a location that didn't cause serious disruption.

Amongst recent failures, I can think of the lineside fires on the ECML; 4492 running out of coal on the way to Bath; an injector failing on Clan Line etc etc. None of those could have been prevented by having better instrumentation giving a read-out to the crew of a looming problem. Many engines with inside cylinders already have "stink bomb" type warnings in the inside big end to warn of overheating anyway.

So what exactly is to be gained by having complicated electronic prior-warning devices? Seems to me like people are trying to invent a solution to a non-existent problem.

Tom

 

Fully agreed - where is the business case? or the need to hang more unrelated kit onto big, dirty, fire breathing, monsters that are such a natural home for dust and vibration sensitive IT kit?

 

Exactly right!

Part of the attraction of the steam locomotive is that it provides a lovely escape from our everyday gadget ridden way overly complicated day to day existence.

We really don't want or need unecessary geekery added thank you!

If you have time on your hands there are plenty of more essential tasks needing attention at a heritage line near you.

 

Seems I've upset the rivet counters.

1. It was only to see if it would be possible.

2. Was only a way to make such a device should it ever be needed.

3 Would want such a device to be discreet.

I had only thought of this on a theoretical basis and so to talk about business cases is inappropriate.
I was looking forward thinking that one day NR might want such assurances so to know in advance what is possible and how to do it has go t to be useful.

Incidentally didn't 34072/70000 have some issues with hot journals last year?

1472

That's a foolish statement to make you do not know me.

I was helping restore and drive steam engines before there was any mainline steam and would have been far more involved in SG steam but for a severe accident in 1968 and still have helped out despite my problems.

I've done my share as much as I was able and suffered great frustration at not being able to do more, such is life.
Anyway enjoy it while you can it's a great hobby if you don't mind getting black but the ladies can be less than understanding especially if you get grease on the carpet.

Cheers Dave

 

Depends what you are doing with the ladies whilst on the carpet! Some like a bit of black and greasy!

:behindsofa:

oo err missus!​