Structure of TID Drawing Office by Gerry Bamford
In its heyday during the 1960's and 70's, TID Drawing Office was a relatively large organisation and during the progress of major contracts such as S.C.A.T, Apollo, Green Ginger, GWS25 etc. comprised a large number of delineators, illustrators and tracers which at times would have peaked at approx. 85 individuals, including a proportion of sub-contract personnel both on and off site. Sub-contractors were located in Colchester, Ipswich, Stevenage, Clacton and elsewhere.
Hut 18 at Baddow was the centre of activities with staff employed in drawing offices at New St, Writtle, Waterhouse Lane, Norwich and Basildon.
Work was highly labour intensive requiring individual craft skills of a high order compared with today’s computerised drafting and printing.
Hut 18 was certainly primitive, it started life as a 1st World War army hut constructed from timber and tarred felt, rotting timber was always being discovered and it was generally agreed that it was only the tarred felt holding the whole structure up. It suffered from damp and very often expensive tracings left on the drawing board would be damp and badly wrinkled by the next morning. Tea and coffee breaks were taken in the canteen as the cramped space in Hut 18 carried the danger of spilling drinks over valuable drawings. Despite its drawbacks, there was always a happy friendly atmosphere abounding leading to many long friendships developing beyond the working environment.
Circuit Delineation:-
The draft circuit diagram produced by the design/development engineer had evolved during the development stage and inevitably contained numerous updates and changes that resulted in a somewhat fragmented and muddled document.
The job of the circuit delineator was to produce a theoretical diagram that conformed to the following parameters
1) Component symbols to conform to standards recognized by the company and our customers (particularly the three services).
2) Drawings to be produced on standard company formats to a size and scale suitable for subsequent inclusion into company handbooks.
3) Most importantly the diagram should be laid out in such a fashion that subsequent users could easily recognize the various functions occurring between input and output and thus facilitate speedy fault diagnosis.
It should be remembered that in the days when nearly all circuit design was analogue rather than today's predominantly digital, fault diagnosis was carried out down to component level which required the maintenance engineer to be aware of circuit function in detail.
Nowadays digital circuitry often contains built-in diagnostics and fault rectification generally comprises printed board substitution at the first level, rather than replacement at component level.
For these reasons the requirement for circuit delineation has decreased dramatically in recent years and is only required where analogue circuitry exists, particularly in the case of high power electronic apparatus.
The following is a list of Circuit Delineators etc. that readily come to mind; it is by no means exhaustive but represents a fair cross-section across the period when TID was at its peak capacity.
Circuit Delineators:- David Collier, Alan Cox, Peter Edelston, Gerry Hagen, Rod Hazel, Ron Ingram, David Johnson, David May, Ron Minor, Alan Pearmain, John Pulham, Mike Walker, Keith Winter, Brian Wright
Illustrators:- Steve Millen
Others:- Ray Brown BEM, Roger Price, Steve Bell
See also Alan Butt