Technical and engineering drawing.

Geoff, Thanks for your comment. Bob Sheppard (from Harper Green Secondary Modern School, in Farnworth c.1946) holds a very important place in my memory.

Tony, I think you’re right. Where are all the responses to the test?

Yes, I think you’re right too Steve. It must be too simple a test.

I have another anecdote for those of you who are enjoying Terry's thread. I must preface mine by saying that Melburnians have an expression about exposing ones posterior in Burke Street, so here goes.

In the late 50's, it became necessary to redesign the outer casing of a toilet cistern. At that time, the casing and lid were being compression moulded from a composite of pitch and other reinforcing materials. The `new’ material was the much more modern thermoplastics polypropylene (PP), and had become commercial around 1957. Unlike the pitch compound, PP could be injection moulded. The specification also included that the existing innards of polyethylene ball valve and syphon, and various metal fittings were to remain.

The cistern casing was designed for both `high’ level and `low’ level operation, and for greater adaptability, was identical left to right. It was necessary with this `new’ material to provide parallel wall thickness by local thickening the five inlet/overflow/outlet positions, thus forming `bosses’ on the ends and underneath.

The next task was to design and detail the tooling (injection moulds). Eventually, I had produced about half a dozen sheets of tool drawings for the cistern’s lower half. These drawings, having passed through the checkers hands a couple of times, and gained approval at various other levels, were sent off to a German toolmaker. Two injection moulding machines were duly ordered and installed, and after about 6 months the cistern and cistern lid moulds arrived.

"Have a look at this!" It was the chief draughtsman.

One of the end bosses was missing! But how could that have happened?

It turned out that on the GA and also in detail, (having sectioned the mould through various planes to show the feed arrangement, water circuits, air ejection, etc. etc.), I had inadvertently omitted to show that the cistern was actually symmetrical about the vertical centre line. The toolmakers had gone ahead and worked exactly to my drawing.

Eventually, the problem was rectified, but by this time I had (coincidentally), taken on a new position with a major raw-material supplier. This company supplied PP, the very supplier of the grade being used for the cistern!!!?

Guess what? The bl . . y cistern followed me there with another problem. But that’s yet another story.

They say things come back to haunt you. But surely not twice. A couple of evenings ago, my wife and I were watching a very early `On the Buses’ episode. Bus driver, Stan Butler was replacing their old toilet cistern with a modern low-level version, and as usual, he was getting into all sorts of bother.

You’ve guessed it!