Not sure if this is the best section to post in, but could someone tell me what the dimensions of boilermaker's pitch and girdermaker's pitch are? It was posted in an old thread, but I cannot find which one; I think one of the spacings was about 2.75 inches.
Attached is info I came across while searching on the net. Sorry for the small text size. I had to screen dump the info and post to a word file. Hopefully this what you are looking for.
... and steel - which was somewhat "empirical" at the time of the source publication.
THE subject of riveting is by no means so simple as might at first sight be supposed, and the author, having had much trouble in collecting and arranging the various experiments which have been published on the subject and drawing thence practical conclusions for his own guidance, thinks that other Engineers, who have neither time nor opportunity for traversing the same ground, may, perhaps, find the following paper a useful resume of our present knowledge on the subject of riveting. ...(BINDON B. STONEY, Civil Engineer and Naval Architect)
-- Edited by Rectalgia on Monday 4th of February 2013 09:14:32 AM
Hmm, this is mind-boggling;would it simplify the matter to ask instead what pitch of riveting was used on the production rhomboids? That would better describe what I actually want to know.
Indeed, and Helen would be your "man" for that. 2¾" is probably close, but as she's counted each and every one of them on the Mk I ... Plate thicknesses increased from the initial 3/8" to something greater in later marks I understand - plate thickness would usually affect rivet pitch but I think any such differences would be slight.
[edit "U+215C Vulgar Fraction Three Eighths" in the Unicode Character Set not supported by the forum. Life is full of such small disappointments]
-- Edited by Rectalgia on Tuesday 5th of February 2013 05:25:05 AM
You're quite right, Helen is bound to know - although if I remember correctly from the old thread (whatever it was about), 2.75" would be the sort of figure for 'Mother', riveted at boilermakers pitch; The girder makers pitch quoted for production rhomboids was somewhat larger, possibly exceeding 4".
Incidentally, I wonder if this post will show as number 600? My counter seems to have stuck at that number recently - it should be more like 605.
I may have looked at every rivet on the MK1 & 2... but even I'm not insane enough to measure them all. :)
Actually, you're right, and it does average out about 4" between centres. In centimeters I found an average of just over 12cm to be about right. Having said that, the range of measurements was from 3.5" to 4.5"
In reality I think 'Girder Pitch' is more of a discription to differentiate the production tanks from Mother. The impression I have of the rivet spacing on the production tanks is that it had more to do with saving time and weight ( there's a lot of them!), than any desire to stick to industry standards. Some spacing is just down to the internal frame and fixtures. Mother had the ideal spacing of rivets, but it would have been almost impossible to get the 100 odd tanks available for when the Army wanted. So once you accept there has to be compromise, no fixed spacing becomes a reasonable one to make.
This is only my own opinion, but I am sure I have read something similar by more learned people in books.