More About Moles

Alex Thomas



I joined Tech Ops in summer 1960 and was quickly put onto cables and monitors. (“C and M old boy” was the instruction).

I progressed to being the fourth man on the mole crane operating the tiller at the back.

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The driver sat on a tiny seat at the base of the jib support column. The whole thing was powered by a 110 volt dc supply which came from banks of rotary generators located in the bowels of Lime Grove.

The supply terminated in a Kliegl connector the width of which limited the amperage that could be taken from the socket. So a pup or a soft light could be plugged in to the same socket as the crane but in theory the socket could not be overloaded.

For reasons of safety the supply was 55 volts positive and 55 volts negative which meant that in theory at least no one could get a lethal shock.

Any earthing of the crane body must have been down the outer of the camera cable.

Of course, things did go wrong. I remember the cable guards running over the power supply cable and cutting through the pos and neg causing a short circuit which dimmed the soft light on that scene.

The other disaster was on the Garry Halliday kids drama series when the bucket of the 4 man Mole caught on the driver’s hand control  and sent the crane fast forward towards the set complete with crew. It smashed into the set but fortunately

Oh happy days.

 

Hugh Sheppard

1.
When the first TV Centre studio (TC3) was about to open circa 1960, I was on Crew 9’s mole crane crew, with the late, great Laurie Duley as senior cameraman. One day a few of us took the familiar trip up Frithville Gardens from Lime Grove on a pre-production mission to test a mole crane on the brand new studio floor. With Laurie on camera, I was driving – from the side as I remember – when we came to a whirring halt. Whirring because a driving wheel was spinning due to the floor not being level and a non-existent mole crane suspension.

As I recall, studio floors were of resin floated onto a reinforced concrete sub-floor, but I’ll stand to be corrected. Anyway, all around us a row broke out between those responsible, which was only resolved when the variation was measured. This turned out to be greater than the depth of the topping, so the sub-floor had to be to blame. While we didn’t realise it at the time, the months of delay were almost certainly hushed up, as I’ve never heard anything about it since. (Has anyone else?)

2.
Back on Crew 6, bucket-swinging for Mark Lewis, and with Andy Tallack driving the now-modified 2-man mole, we were working on a “Music for You”. probably in the same studio, live as usual.

During rehearsals, the director asked for Camera One, Mark on the mole, to do a long traverse between shots for which there wasn’t much time. Starting with the bucket high and the jib at right-angles to the body (with me off the platform) at the end of one shot, we had to motor about forty feet for the next and put Mark high above the orchestra for a close-up on the bassoons. When Mark didn’t quite get there, he called for the mic. and explained: “I’m sorry, but my boys can’t make it”.

That was a red-rag to Andy and to me, so we countered with “Oh yes we can”, and the sequence stayed in.  Come transmission, Andy shot us backwards when the red light went out, then forwards and to the left and right, while I somehow climbed back on, heaving the bucket down as Andy brought us to a halt. But it had been too much for Mark; losing his footing and with the director shouting “On the bassoons, Mark; on the bassoons” he hung there, slowly spinning and with the camera facing the wrong way.  A real ‘Oh my paws and whiskers’ moment, and one I’ll never forget.  

 

John Wardle

As far as I remember the studio floors at TC were originally thick linoleum laid on a screed over concrete until we changed to self-levelling resin. When we changed to resin this caused static problems and affected some cameras. The linoleum was always being damaged by the scene boys dragging sets across the floor. The change to resin was after I moved to Technical Investigations so must have been after 1972. I remember doing floor level tests with either a Mole or Heron.

 

Nick Ware, Alec Bray


“…we had an ex-Beeb Vinten motorised dolly…”

which leads to an interesting thought … The elevation of the Motorised’s Jib was purely down to the grunt of the motor (presumably with a worm drive?).  Unlike the other Vinten products that I came across in my time, where "balance" was the keyword!

 

Chris Woolf

Oh no! There were some gert great springs to at least help!

 

Nick Ware

In which case, did the motor have to work harder on the way up, or on the way down!?

 

Chris Woolf

… Depended on how fat the cameraman was!

 

Nick Ware

But seriously though, I’m wondering if the Vinten motorised was designed by a mechanic or a physicist. The jib is a Class 3 lever, and so presumably is the spring. To my thinking, surely regardless of the cameraman’s weight, the motor has to work just as hard on the way down to compress the spring. That energy being equal and opposite to that saved by the spring on the way up. So from an energy point of view does the futty-gert spring serve any useful purpose at all?

The Mole crane, on the other hand is a weight-balanced Class 1 lever with its fulcrum in the middle, so doesn’t require energy to move it up or down, other than to overcome initial inertia.

Am I over-thinking this, or should I just go and mow the lawn?

 

Chris Woolf

And equally seriously, because this reminds me of the excellent over-coffee discussions that one had when coffee breaks existed…

The effort required to move the cameraperson/platform load is the difference between gravity shoving the load down and the spring shoving the load up. In essence it is a (roughly) balanced system, with the Class 3 positioned spring taking the place of the Class 1 positioned counterweight.

The difference is very much smaller than the absolute load of the arm/platform casting, camera and cameraperson’s beer gut, so a much smaller motor can be used. This is exactly the same as a lift motor – that only has to drive the difference load between cage and counterweight.

Yes, your energy balance argument is correct, but since gravity would be doing all the work coming down if there was no spring, the motor would have to do all the work going up…  Gravity is free but the electric motor and the power we feed to it are not, so it is better to "waste" gravity and "save" on the leccy.

Keep thinking and mow the lawn!

 

Bernie Newnham

I do seem to remember that waving Mole crane arms around did in fact take quite a lot of energy.  And the incident with Gillian Lynn, when she wanted us to stop the Nike arm instantly, rather showed that indeed inertia was something important too. I never was much good at physics, but I did put in the waving time – 

more_about_moles_bernie

 

Alec Bray

From the context, I am guessing that the crane Bernie is  swinging is a Nike?  I never saw one of those.

 

Pat Heigham

That looks like Glenda Jackson on “Morecambe & Wise”?

And is that Eddie Stuart in the white cardigan? Could be when he came off Crew 3 – usually on the Mole in TVT, to switch to production.

 

Paul Thackray

Nike had a longer reach (Min / Max height etc) and required 4 man crew (Mole was 3 man).

Powerwise,  Nike was a 240v 13 A (a Lead Acid  battery charger) , whereas the Mole was 110v dc!

 

Graeme Wall

On the subject of cranes, the Mole had a 1:1 arm but the Nike was a 2:1 arm necessitating double the amount of lead in the bucket to balance the camera and cameraman on the other end.  If I recall correctly,  the Atlantic was the same.

 

Paul Thackray

These might be of interest:

Mole Crane Code of Practice” issued in 2000.



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Operational Use of the Chapman Nike Crane“:



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[Ed: the “Mole Crane Code of Practice” was up-issued in 2000 – a good half-century after the Mole was introduced into television studios…]

 

Alec Bray

These are of very great interest!   Interestingly, there was not, as far as I know, any code of practice for the Mole when I was at the Beeb.  And the Code of Practice  refers to "… The Mole Crane…" whereas in my time Tech Ops management always referred to it as the MRPC Crane!  (Motion Picture Research Council Crane).

 

Roger Bunce

Never knew why the [Mole] "Ramp" at TV Theatre was so called, since it had no slope!

 

Pat Heigham

I saw the show [“42nd Street” at the Theatre Royal, Drury Lane] 10 times, with different sets of friends, but always seated in the Royal Circle, as from my days in the TVT, the main wide shot was from the Mole craned up to the level of the dress circle – so I reckoned on that being the best angle!

 

Peter Hider

Chris Morahan was a very demanding director and I remember helping the crane swinger to do a crash descent on the Mole when the mum, played by Marjorie Mason, committed suicide in the kitchen. We hit the ground so hard, the camera tube(s) flashed to black and the back wheels of the Mole lifted off the ground. It was a quartet of plays each of which told the same story from each family member’s point of view.

The father was played by Maurice Denham and Judy Dench’s brother by Peter Bryant. [“Theatre 625: Talking to a Stranger”]  really was one of the pinnacles of that golden era.

 

Roger Bunce

[Here are entries] from a ‘Camera Data Book’ we compiled years ago. I started typing it up for Bernie’s site but never completed it (it will have pictures eventually). Purely statistical stuff, no explanations of how things work, I’m afraid.



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Alec Bray

[That] data book [has] lots of useful facts and figures in there… One tiny omission – what was the maximum speed of the Mole, Heron etc ?  I think that the Mole could do about 8 mph – does that sound feasible?

 

Roger Bunce

Uphill or Downhill?

I know the maximum acceleration of a Mole Crane is 9.8 meters per second per second . . . as with any other object when dropped off Beachy Head.

We did most of the measurements ourselves, but speed would have difficult to measure, even if we’d had management permission to try. "Hey, we got it up to 15mph, before it ripped the plug out of the wall! – and smashed into the opposite wall!" So, your guess is as good as mine. I remember doing some delightful slow tracks, by getting off and pushing it manually.

 

Alan Taylor

Mechanically minded bods may be interested in the Chapman Titan crane, which was mounted on an amazing lorry.  The counterbalance for the camera crane was adjusted my pumping massive quantities of liquid mercury into a tank on the opposite end to the camera.

The lorry part featured all wheel steering which meant that it could crab or manoeuvre in all sorts of weird ways.  It could also drive along at a fair speed too.

I recall working on a dance routine for the Engelbert Humperdinck show around 1970 which was being shot on the set of the Oliver movie.  Stewart Morris was directing and unsurprisingly, he insisted on having the biggest, bestest camera crane available, so a Titan was booked. Even with it’s super agility, it was a huge challenge manoeuvring it into the desired place on the set, but unfortunately what looked like a solid stone pavement turned out to be painted wood and was utterly crushed under the wheels. 

 

Pete Hider

The Transatlantic had a further element in its arsenal. The column on which arm was mounted could also tilt. I was on the camera elevated to the maximum on the arm being a German Zeppelin over London during WW1.I could touch the grid which was fairly scary when the Trans. driver demonstrated the column tilt. It was very nearly brown trousers time. I think Steve Rogers (the Omar Sharif of Tech Ops) was my chair turner.



 



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