Lucien's vintage fairground electrics thread

[Lucien Nunes]

In which we can discuss and reminisce about such wonderful and fascinating subjects as:

• The origin of the Ward-Leonard speed control system
• Speedways, octopuses & big wheels
• Old British trucks
• Summer evenings, girls & candy floss
• Orange 2-pin plugs
• Tungsten light bulbs
• Mather & Platt dynamos

etc.

A few of my past posts have hinted at an interest in fairgrounds and their people and machines. IRL it's more than skin deep and goes back as far as I can remember.

Before we start: Not all the pleasures that can be had at the fairground are compatible with one another. I wrote the following in a post 8 years ago and it is still important:

.... standing between two of these on the back of an old Scammell ballast tractor, hot and oily after running all day, lighting set throbbing to the beat of 50's R'n'R ....don't do this when at the fairground with your other half. I did, and it was difficult to convince her to share a waltzer car with with someone covered in soot who smells of diesel....
** I have since learned that most girls don't go to the fair to fix injection pumps with their mates **

Hold on tight, keep your arms inside the cars....

 

[OnlQQker]

 

[ipf]

Mather and Platt. I remember discussing the Manchester Dynamo, years ago. They were used in textile mills around here. Basically Edison's generator, so dc, it was a big development on it for higher output in the cotton mills.

 

[Lucien Nunes]

I was going to start by posting assorted pics of interesting and historic equipment, but due to having a very rough week with chemo and various other new health issues, I can't get the pics, the scanner and myself all together. In truth I'm finding it difficult to get myself together anyway.

So I am going to fill in by introducing this picture - the terminal box cover used on many Mather and Platt machines - by way of a blueprint held in the collection at the National Fair and Circus Archive.

Terminal Box Blueprint

cdm15847.contentdm.oclc.org

If you've been to a few steam rallies you will have seen this cover plate - shown bottom right - on the front of the dynamos on various showmans' engines, usually with the details picked out in contrasting paint. But what does it all mean?

It shows four ways of connecting the machine - clockwise generator, anticlock generator, clockwise motor and anticlock motor - according to the purpose for which you want to use it. Obviously once a machine is perched on the steamer's smokebox extension, its role is fairly well carved out as that of a generator, but the fact that they show these options right there on the casting is a reminder that at their heart, DC generators and motors are basically the same thing. Why, then, the different connection options? Does the direction not relate to polarity, as it does on most DC motors that one might play with today?

Who's interested in a bit of DC machine theory, or would you prefer just to wait for some colourful pics?

 

[pc1966]

Ah, has been some time since I last looked at any Ward-Leonard systems!

 

[Darkwood]

I recall when I came across a ward Leonard setup and we had a convo' on here I think, it takes some getting your head around and hands up to him.

 

[Lucien Nunes]

The Ward-Leonard system was the 'classic' application of variable-voltage generators as variable-speed DC drives for lifts, industrial plant etc. But another early application of the variable-voltage generator was to drive the huge, heavy scenic railway rides that evolved out of the steam switchback, popular in the 1910-1930 era. For rides like switchbacks that can be significantly out of balance at rest, direct drive by steam is practical because a steam engine can develop full torque at negligible speed and pull away under fine control. The scenics had large multi-seater electrically-driven cars on a track traversing very steep inclines that demanded equally high torque at low speed, but this time an electrical control was needed. In due course I will tell about that, and the special 'scenic' showman's road locos developed for the purpose, but we'll begin tomorrow with a closer look at those Mather and Platt dynamos that were so often at the heart of the system.

 

[OnlQQker]

It's funny really, there we were going along quite happily in life with horse/cart and a barge, and through the power of money mixed with a tiny fraction of steam, inventers went and made every body extremely unhealthy and following a path they laid for there own wealth.
Not the inverters fault though, what they should of done is invented it and kept it to themselves.
That way they could of pulled nothing but there own hair out every time it went wrong.

Sorry, I've gone right off topic.

I'm extremely interested to hear more about the variable speed DC drive for lifts, great post btw.

 

[Megawatt]

In which we can discuss and reminisce about such wonderful and fascinating subjects as:

• The origin of the Ward-Leonard speed control system
• Speedways, octopuses & big wheels
• Old British trucks
• Summer evenings, girls & candy floss
• Orange 2-pin plugs
• Tungsten light bulbs
• Mather & Platt dynamos

etc.

A few of my past posts have hinted at an interest in fairgrounds and their people and machines. IRL it's more than skin deep and goes back as far as I can remember.

Before we start: Not all the pleasures that can be had at the fairground are compatible with one another. I wrote the following in a post 8 years ago and it is still important:

.... standing between two of these on the back of an old Scammell ballast tractor, hot and oily after running all day, lighting set throbbing to the beat of 50's R'n'R ....don't do this when at the fairground with your other half. I did, and it was difficult to convince her to share a waltzer car with with someone covered in soot who smells of diesel....
** I have since learned that most girls don't go to the fair to fix injection pumps with their mates **

Hold on tight, keep your arms inside the cars....

My wife and I went to an amusement park many years ago and rod a ride which spends everyone around all the time. The problem I think that it was going so fast it was mashing everyone against me and I was sitting on the outside next to the rail and I started screaming like crazy to stop the ride. That happened before I came an electrician. Knowing what I know now I’m suspecting that there must have been some kind of VFD which was probably not working and they bypassed it so that big motor was flying. It felt like 3600 RPMS. Is that possible @Lucien Nunes

 

[Lucien Nunes]

I suppose it depends on how long ago that was, but I must say that I'm not familiar with the normal practice in the US for amusement park power and drives. In the UK, as far as travelling fairs and carnivals are concerned, we have been very traditional. Well into the 1990s and beyond, 110V DC power was standard for everything except the music systems and many of the older rides had electrical equipment dating back 50 years or more. A simple rheostat would serve as a starter for the main motor's armature, examples of which I will soon post. Only really in the last 25 years have we seen widespread use of AC / VFD drives for travelling rides and some still use their original DC motors driven from rectifiers. Permanently-installed theme park rides are more likely to have been AC-driven from new, and technically more up to date. Once I've got a few pics up, you might be able to draw some comparisons between our 'olde-tyme' methods and what you do in the US.

This thread has got off to a slow and picture-less start because I have been mainly in bed trying to sleep off the chemotherapy. It has always been a dream of mine to own an old ballast tractor, perhaps a 1960s Scamell or ERF, with a pair of traditional Showman's generators mounted abreast in the conventional way. It was definitely in the list of top 10 things to do before I die, but it's not looking likely to happen now. I do have a couple of vintage sets and if Edward and I can get one of them to a show next summer and actually make some power with it, and we can sit on the grass sipping a beer listening to the old diesel rumbling gently, no matter what else happens, I will be 100% happy with that.