Background
More information and pictures about transmitter towers in general, Eagle towers and the 150lb Balanced pair circuit in London.
John Howell
The tower vehicle looks like an original fire engine. The picture comes from the 1939 BBC Handbook (which covers activities in 1938). It states that “…August saw the addition of a second mobile television unit … ” consisting of three vehicles. “… Another addition to the fleet is a fire-escape ladder which can be run up to a height of 100 feet in a few minutes….”
The covering text reads:
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(Click on either image for a clearer view)
Mike Jordan
Interesting one this. It certainly can’t be called an “Eagle Tower” as those were specially manufactured by Eagle Ltd and were the 60ft vertical things. Before these there was the 60ft (?) vertical one apparently “stolen” from the Germans after WWII – the vertical “Rommell tower”.
The PTAs (Powered Transmitter Aerials) KGA 565 and KGA 566 were true Merryweather fire engine chassis and had the sliding fire escape ladder with an aerial on top (just like the 68 Mc/s one in this picture) and containing the huge transmitter and an onboard generator that could be used to power the scanner. PTA2 (566) had an aluminium body to keep the weight down.
The one shown looks like a very small chassis and the tower must have extended well over the front/rear. There doesn’t seem to be any space at all on the chassis for the transmitter and so I guess it would have been in the nearest adjacent vehicle.
These were finally replaced on the 70s by new chassis including a technical area with a 100ft version of the Eagle Tower on and then later by Simon Hoists.
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The 150lb Balanced pair referred to in the book was installed as well to connect various London OB sites and one last bit was still in use for the reverse vision to BBC Norman Shaw North (predecessor to Millbank) for news up till they moved out.
It appeared on normal mains 15Amp Niphan connectors (seen still labelled at bottom of Queens Gate photo) and at Earls Court (both taken by me so only ever so slightly old).
This circuit would probably have been used for this OB from The Cenotaph when it was inaugurated.
I was once at Apsley House (number 1 London) and a new BT “lad” who didn’t even believe video could go down a coax rather than fibre was totally discumnockerated by seeing it still existing from 1937ish and knowing its history.
Robin Sutherland
Other old transmitter towers were lovely vehicles based on an AEC coach chassis with a single drivers cab and a Merryweather fire escape ladder mounted at the rear.
These were post-war (but only just) and were in service until the mid 1970s. There were two, PTA 1 & 2 (PTA = Power Transmitter Aerial).
They had teething troubles with the new tower vehicles and 1 & 2 soldiered on for a while until it was sorted. One was travelling to Burghleigh Horse Trials and the rigger driver stopped for a cuppa at a transport cafe on the A1 where he was asked by other drivers if he was on his way to a Historic Vehicle rally! A shame neither survived – they were very attractive and unique vehicles.
Mike Jordan
Here are another couple of stories!
Ron Alloway (R/D who was once hauled over the coals for behaving unsuitably rudely to the garage supervisor but was ace at training new recruits) was driving (probably unsuitably fast) one old PTA down from KA to the Uxbridge Road. Stopped as he arrived and the tower (which was extended by wire ropes) slid out across the Uxbridge Road as the peg that sat up from the cab to stop just this happening had sheared off! One nice road block!
My first OB on my own at KA (wow 1971!!) was at Chelsea FC when we used to park on a sloping ramp at the south end behind the stands. I inadvertently let the tower extend further than the bell which showed the limit where one had to stop to give a bit of “slack” to go a tiny bit further to release the pawl which interlocked the extending gears. Come the de-rig therefore panic! A handy Rigger supervisor (Les Edwards) went in with a crowbar to lever it out and told nearby rigger to operate the “Extend” lever. He unfortunately operated the “Erect” lever at which point 100ft of tower started to drop itself across the scanner roof!
Well, a good start to an OB life!
