vacuum braked passenger cars

[Alan Marshall 1Participant @alanmarshall1]

Sorry if the subject is not a locomotive but ther is nowhere else to deal with rolling stock…….

My question is: is there any Society running braked passenger cars for public hauling that has a specification or data that deals with the acceptable braking efficiency of a passenger car?

The question arise because of the usual H&S issues surrounding public passengers (or perhaps any passengers for that matter). The question is not simple of course as car loading, speed, brake type ect all have a bearing but in the end would something simple like a loaded car(specify weight) must stop in X feet when the brake is applied at Y mph?

Replies on a post card!

Alan

[Alan Marshall 1Participant @alanmarshall1]

[MICHAEL WILLIAMSParticipant @michaelwilliams41215]

Hi Alan ,

Don’t know of any specific requirements for braking on smaller scale railways .

I’ll say at once that problem you may now have is that an army of jobsworths will read your post and decide that a raft of regulation is nescessary – and I’m not joking .

Seriously there are safety regulations for full size railways , larger scale public park railways and fairground rides but these are set down in publications inches thick – don’t go there unless you have to .

As far as the normal club track carrying passengers is concerned you need a very simple but integrated safety plan .

Braking would be only part of this .

I think you could start in a different place and think in terms of number of trains on track at same time and the minimum headway between between trains .

Braking requirement is then that which will stop heaviest train in a shorter distance than minimum headway .

As regards stopping to avoid obstacles and people in wrong place there is not much you can do except to have adequate barriers , clean up teams and marshals in place at all times during public running .

Rquired stopping distance for not hitting random obstacles could easily be zero and that is not achievable so use common sense to set down viable minimum for a true emergency stop .

More important really than stopping distance is ensuring that brakes work reliably so maybe a maintenance record for each car .

The above written down clearly with policy on running speeds and and approved driver will probably be ok for an insurance based risk assesment .

Please don’t think that I support or approve of all this mindless red tape requirement but it’s the real world today I’m afraid .

Regards ,

Michael Williams .

[martin perman 1Participant @martinperman1]

Alan,

If you contact Northampton Model Engineering Society **LINK** somebody maybe able to help, they have public running days and I know their rolling stock is fitted with Vacuum braking as my friend, a member, made and fitted the parts to some of the trucks.

 

Martin P

 

Edited By martin perman on 23/03/2014 12:44:58

[Alan Marshall 1Participant @alanmarshall1]

Michael,

Could'nt agree with you more.

All of what you have said is already catered for in some form or other and we run a documented H&S policy… albeit embryonic (but still cm thick) at the moment but getting better…….

It's interesting that lots can raise H&S questions… but few if any have answers!! But once a questoin is asked it means that a "reasonable man" needs to make endeavours to provide an answer…. for the record of course!!

We have been successfuly pulling public for many years now and all this H&S is becoming a nightmare; not just for us of course. Pity the litigation culture of the USA ever hit our shores because that is always the argument or should I say fear, whereas previously common sense on safety worked well enough.

The original concept of the H&S at work Act has long been lost I think.

[Andy AshParticipant @andyash24902]

Surely someone should just think about a bit of basic physics before wielding the H&S stick?

I don't really know why some people are trying to apply full size railway rules to miniature railways. They're just not the same, and physics says so.

Kinetic Energy = 0.5mv^2

If an accident occurs then the energy dissipated to achieve rest (and that which will cause harm) is expressed by this function. If a 5" miniature locomotive achieves 6mph it's doing well. If it's full size brother gets to 60mph, it's a bit slow. Even then, the speed is 10 times greater. A full size locomotive travelling at 6mph would have 1/100th of the energy.

Then, in the full size system, a carriage might be 400 times heavier than an individual passenger. On the 5" railway the carriage weighs something less than the weight of one passenger.

If something goes wrong and a collision occurs in full size, the fear is that a carriage would damage a passenger through deformation, confinement, and fire. At 5" gauge that is unlikely due to relative lack of energy, lack of mass, lack of combustibles and open carriages. Actually the worst that is likely to happen in a collision, is that the driver ends up sitting on top of a hot boiler.

Braking on a 5" railway is almost irrelevant, save that a train can be made to stop in order that models do not become damaged. In the worst case you can probably use your feet to stop.

As the sizes become larger, more consideration is needed.

If speeds increase, much more consideration is needed.

Actually, the big hazard with miniature railways is *loading gauge*. Ideally track furniture would be arranged such that no body part of the largest person can reach any stationary part of the railway from a moving carriage. If, god forbid, someone were to lose part of a limb it is very unlikely that a better braking system would avoid it.

That parents often choose to carry their kids in their arms, and even hold them out whilst on the move, never ceases to amaze me. I also find it incomprehensible that they often resent corrective instruction.

 

Edited By Andy Ash on 23/03/2014 15:45:38

[Ompa OmpaParticipant @ompaompa11814]

Please, and I really do mean it, think very hard before setting out on the provision of vacuum brakes on your passenger cars. At my own club many years ago a 'jobsworth' on the committee decided that these brakes would be beneficial. How wrong he has turned out to be. Following months of retro-fitting a system more months of trouble shooting and correction took place. We run a simple 5 inch gauge system, normally only hauling one car with up to six or in the case of small children eight at a time. Over the years they have been fitted they have never really had to prove themselves. Also over the years they have been fitted they have given more trouble than they are worth. Recently we have had numerous arguments and debates about them and nobody can really come up with a full proof method. As a consequence on many occasions they are disabled and drivers drive using their own judgements and 'skills' in controlling their own trains. I know several cluibs have fitted them and make them work, but are they really needed? If a driver uses his 'skills' in driving then there is no need, especially on many club type tracks. If a driver is always driving too fast and up against the rear of the train then vacumm brakes will do nothing, but a reprimand and eventual barring of that driver will. One supporter says they are useful in the case of a 'breakaway', opinions are divided on this, saying that if correct couplings are used between locomotive/tender/driving car/ and passenger cars then this does not normally happen. Sorry to be so vociferous but after so many years suffering at the hands of 'jobsworths' I really think they are a waste of time in anything up to and including 5 inch gauge operations. Stan B.

[Simon CollierParticipant @simoncollier74340]

We run a 5" gauge railway with vacuum braked trains. The locos pull up to 7 passenger cars plus guard's van, weighing up to 2 tonne, and the steepest grade is 1:60. On a busy running day, we give over 3000 rides in an afternoon. The braking system gives very little trouble. The engines' ejectors are used to apply the brakes, whereas ideally, the vacuum would keep the brakes off, for fail-safe operation, but this is how the system has evolved and it does work very well.

http://www.slsls.asn.au/

[julian atkinsParticipant @julianatkins58923]

we have vacuum fitted stock on our ground level 7.25"g. if the loco isnt vacuum fitted the passenger/guards car has batteries fitted to create the vacuum. with usual loads of 30 passengers relying on loco brakes and handbrake to driving car is not an option.

for the raised track of 3.5"g and 5"g train loads are lighter and the driving trolley handbrake is sufficient.

i have a few locos fitted with vacuum ejector in 3.5"g and 5"g but the club passenger trolleys arent so fitted.

the Reeves/Brian Hughes design of passenger trolleys incorporates vacuum brakes and can be thoroughly recommended if you are so inclined. same were described by brian in ME 1990.

all the local clubs in my area require vacuum brakes for ground level 7.25"g

cheers,

julian

[Ompa OmpaParticipant @ompaompa11814]

So it does come down to personal choice and type of passenger (size) in operation. What we have found also is the material the track is made of affects performance. Ours is aluminium and given any damp or oily surface conditions the brakes may come on (if fitted and used) and often the entire train just skids along until enough friction is generated between all wheels and rail, so no use in a dire emergency!

Edited By Ompa Ompa on 24/03/2014 10:42:38

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