I'm on the road at the moment so unable to give the exact difference between UK and US drawing standards, but the change was to bring the drawings into line with US engineering practice. Of course Packard also introduced their own mods, supercharger drive, mags and pressure carb that didn't cut out with -ve "g". One major issue facing Packard was having to manufacture dies, taps etc in order to keep the British threads on screws, nuts etc, which led to some delay in the program.

From an engineering point of view, straight cut gears are a better engineering solution to any gearing situation because they do not impose any side loads as do helical gears. One of the costs is noise, lots of it. Take a look at racing cars.

I'm a big fan of IKB, but I think he was a good engineer, but a superlative project manager. The latter was his real skill.

For a superlative technical engineer, I think my money would be on Barnes Wallis - who also was a brilliant manager and networker, the latter being at the root of so many of his successes.

When he designed R100, he managed 11 discrete parts in the entire 72ft/33ft framework (50 if you separate by material gauge). You'd struggle nowadays to find many aeroplanes with that few discrete parts in a door!

Which is not to denegrate Hooker. We were privileged in Britain to have a group of incredible engineering geniuses at that time: Mitchell, Hooker, Camm, Wallis, Shilling.... Comparing them is an interesting intellectual exercise, but the reality is that in their own sub-fields, each was unsurpassed.

G

and underfunded.

The main difference is the UK, and most of the rest of the world, uses first angle projection and the US uses third angle projection. I had to look that up - it's nearly 45 years since I had to make something from an engineering drawing so don't ask me to explain the difference now! I did know...

As I said, I've no idea if Packard based their drawings on Ford's or RR's but since there was already a set in existence with mass production tolerances it would seem a bit daft to start again. Time was short and according to Hooker it took Ford a year.

IIRC, Packard didn't want to make their own taps and dies but nobody else had the capacity so they were left with little choice.

My recollection of being on drawing board in the UK 1960/70s is that we pretty much always used 3rd angle. 1970/80s in the USA I was trying to sell them CAD programs and only did examples for training -- do not remember anyone saying I was using unusual projection.

It is whether you draw a projected view on the side from which you are looking (3rd) or on the side towards which you are looking (1st).. There also exist 2nd and 4th angles, but I have never seen them used and cannot remember what they were. In case of possible misunderstanding in both BS and ANSI codes it was allowed to have a labelled arrow and (eg) VIEW A under the projected view.

If you like Not much of an engineer can I suggest It Was Fun: My Fifty Years of High Performance by Tony Rudd.Designer at the BRM and Lotus F1 teams.


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Having spent my formative years in the drawing office at Farnborough using first angle drawings, we all knew about third angle, and so long as we knew that was what it was, had absolutely no trouble using them.

G

G,

Thanks. You've answered a question I was going to post. I had never heard of first and third angle, but after reading about them, I thought "Why waste a year? Why not just teach the craftsmen how to use first-angle?"

My recollection from Hooker's book was that Packard needed more precise drawings in order to produce interchangeable parts.

A site that provides a good oversight of the Merlin production and issues.

https://aviationshoppe.com/rolls-roy...ies-p-254.html

megan,

Thanks for that excellent link. I was a bit confused at first when I saw an ad for a blueprint, but then I realized that I had to scroll down to see the text.

What I don't see mentioned in literature on the Merlin is the Australian project for manufacture. What little I can glean is the Merlin 102 was produced for installation in Australian built Lincolns. Be interested if anyone has gen, particularly numbers built.

https://cimg4.ibsrv.net/gimg/pprune....ff6cb6d512.jpg
https://cimg4.ibsrv.net/gimg/pprune....7aac0a3a34.jpg