Ever wonder how they did computing before computers?

[Peri]

I found this fascinating - how fire control computers worked in navy battleships in WW2.

Using cams, gears, differentials and other types of mechanics to do maths - some of it pretty advanced.



Part 2

 

[OldGreyDog]

My first job after leaving school was in a structural engineering office - we used slide rules for calculations. Other names for them were guessing sticks and logs’ on a stick. I still have my full size one and two or three half size ones in nice leather slip’s which the company used to give to clients.

 

[AES]

Yup, me too. And we called them guessing sticks or slip sticks too.

But I'm talking early '60's when I started my apprenticeship.

But back in the same era as the Naval gunfire vids (thanks for posting those BTW, fascinating) various things on WWII bombers and fighters (bomb sights, gun sights, etc) were also all mechanical - gyros, cams, gears, springs, etc, etc) As was the famous Top Secret American Norden bomb sight.

And if you go back further - 1920's & '30's, and read Nevil Shute's "Slide Rule" (just one example), all the stress calcs on each structural element of the UK's R100 airship framework (the "caplitalist airship" that didn't crash!) were all done by a team of "calculators" working with circular slide rules and mechanical adding machines ("Computators" I think they were called - they weren't even electric, you had to turn the handle "X" number of times).

And now apparently, my smart phone has more computing power than NASA had for putting men on the moon in 1969.

 

[OldGreyDog]

Yup, me too. And we called them guessing sticks or slip sticks too.

But I'm talking early '60's when I started my apprenticeship.

But back in the same era as the Naval gunfire vids (thanks for posting those BTW, fascinating) various things on WWII bombers and fighters (bomb sights, gun sights, etc) were also all mechanical - gyros, cams, gears, springs, etc, etc) As was the famous Top Secret American Norden bomb sight.

And if you go back further - 1920's & '30's, and read Nevil Shute's "Slide Rule" (just one example), all the stress calcs on each structural element of the UK's R100 airship framework (the "caplitalist airship that didn't crash!) were all done by a team of "calculators" working with circular slide rules and mechanical adding machines ("Computators" I think they were called - they weren't even electric, you had to turn the handle "X" number of times).

And now apparently, my smart phone has more computing power than NASA had for putting men on the moon in 1969.

Very interesting stuff. I can only go back to 69’ as thats when I first encountered a slide rule. We all had them and used them for almost everything. There was a basic electric-mechanical adding machine in the office which was used for adding up the total length of reinforcing steel in concrete units. I also had a little brass pocket abacus thing (operated with a small brass stylus) for basic adding up! One of the guys in the office had a circular slide rule - the envy was real!

I’m vaguely aware of gyroscopic sights/controls in old military equipment and ordnance, fascinating subject, but I have no real understanding of how they work.

 

[kinverkid]

And now apparently, my smart phone has more computing power than NASA had for putting men on the moon in 1969.

Talking of computers and the moon landing. An excellent read and very good film to watch is Hidden Figures written by Margot Lee Shetterly about the black female human computers that helped in the NASA programme.

 

[Stuart Moffat]

My Aunt, Isobel Moffat born in the 1920s had the job title “computer” at the local council.

 

[J-G]

read Nevil Shute's "Slide Rule"

Just ordered a copy from eBay.

 

[Devmeister]

I date to the HP41CV. Best damn eng calculator ever! My buddy who has past used slide rules. He was a surveyor on the 14 mile Adams Tunnel under the continental divide of the Rockies. They had two bores: one on each side of the divide. When the bores met, he was off by less than 3/4 of an inch!

 

[Devmeister]

Talking of computers and the moon landing. An excellent read and very good film to watch is Hidden Figures written by Margot Lee Shetterly about the black female human computers that helped in the NASA programme.

Crazy! MIT designed the moon landing computer and Raytheon built it from discrete 74 series TTL chips. Damn thing spit out overload errors in middle of moon landing. Had to switch off long range radar to get a bit more poop in the pants to complete landing. But Armstrong was one of the best throttle Jockies out there. A real sled driver! A pilots pilot! Proof we still need spam in a can when the bits go on vacation!

 

[MorrisWoodman12]

I remember at school and college having slide rules for all my calculations back in the early 60s.
My mother, grhs, was a comptometer operator and worked for many a year at a quantity surveyor in Braintree in Essex. I remember seeing the comptometer occasionally when she brought work home. It's basically a mechanical adding machine with row upon row of keys numbered 0 to 9 on the front. She would bang away at the appropriate keys for the correct number of times to add and/or multiply things for the correct calculation. She knew the decimal equivalent of all fractions at least to 64'ths and maybe further - just knowledge needed for the job. With all the sophisticated computer programmes these days people don't know the're born.

 

[MikeK]

I used to travel a lot and listen to history-related podcasts. One of the best Apollo program documentaries I remember is Kevin Fong's 13 Minutes to the Moon by BBC World Service.

Episode Five is "The Fourth Astronaut" and goes into detail about the first portable digital computer developed by MIT.

 

[DBC]

Yup, me too. And we called them guessing sticks or slip sticks too.

But I'm talking early '60's when I started my apprenticeship.

But back in the same era as the Naval gunfire vids (thanks for posting those BTW, fascinating) various things on WWII bombers and fighters (bomb sights, gun sights, etc) were also all mechanical - gyros, cams, gears, springs, etc, etc) As was the famous Top Secret American Norden bomb sight.

And if you go back further - 1920's & '30's, and read Nevil Shute's "Slide Rule" (just one example), all the stress calcs on each structural element of the UK's R100 airship framework (the "caplitalist airship" that didn't crash!) were all done by a team of "calculators" working with circular slide rules and mechanical adding machines ("Computators" I think they were called - they weren't even electric, you had to turn the handle "X" number of times).

And now apparently, my smart phone has more computing power than NASA had for putting men on the moon in 1969.

Interesting, they used some low tech solutions for bombing too. I think I am right in remembering from Paul Brickhill’s book that the bomb aimer knew it was time to let go of the bouncing bomb on the Mohne Dam raid when the two towers on the dam parapet lined up with two nails that had been hammered into a peice of timber. All this while the pilot was judging his height off the lake water using two converging spotlights hung under the plane.

 

[AES]

Interesting, they used some low tech solutions for bombing too. I think I am right in remembering from Paul Brickhill’s book that the bomb aimer knew it was time to let go of the bouncing bomb on the Mohne Dam raid when the two towers on the dam parapet lined up with two nails that had been hammered into a peice of timber. All this while the pilot was judging his height off the lake water using two converging spotlights hung under the plane.

I've read the same. Not only in Brickhill's book, but others too. "Obvious" and "simple" really - once someone else has thought of it!

If you haven't done so already, I'd strongly recommend those interested in this thread to go and look - again? - at the OP's two vid links. Quite remarkable really how complex calculations were mechanised, and a prime example of "Oh, that's pretty obvious - to start off with anyway - so why didn't I think of it?"!

 

[shed9]

I used to travel a lot and listen to history-related podcasts. One of the best Apollo program documentaries I remember is Kevin Fong's 13 Minutes to the Moon by BBC World Service.

Episode Five is "The Fourth Astronaut" and goes into detail about the first portable digital computer developed by MIT.

Have you seen Apollo 11 yet by Todd Douglas Miller? Utterly outstanding film and just incredible use of actual footage.

 

[Fergie 307]

I've read the same. Not only in Brickhill's book, but others too. "Obvious" and "simple" really - once someone else has thought of it!

If you haven't done so already, I'd strongly recommend those interested in this thread to go and look - again? - at the OP's two vid links. Quite remarkable really how complex calculations were mechanised, and a prime example of "Oh, that's pretty obvious - to start off with anyway - so why didn't I think of it?"!

So often the case with some genius ideas, they seem blindingly obvious once someone has done it. How many hundreds, or even thousands of years did people roll things on logs before someone had the idea of cutting off a slice of log and calling it a wheel?

 

[shed9]

So often the case with some genius ideas, they seem blindingly obvious once someone has done it. How many hundreds, or even thousands of years did people roll things on logs before someone had the idea of cutting off a slice of log and calling it a wheel?

I'd argue it was the axle that was the game changer. As you point out, they already had the wheel naturally.

 

[Pedronicus]

..... and mechanical adding machines ("Computators" I think they were called - they weren't even electric, you had to turn the handle "X" number of times).

I think they were called "comptometers". My mum was an operator of one in the late fifties.

 

[AES]

Yup, I think you're right, thanks.

 

[MikeK]

Have you seen Apollo 11 yet by Todd Douglas Miller? Utterly outstanding film and just incredible use of actual footage.

Not yet. I see it is available on Sky Documentaries.

 

[Sandyn]

An early example of an analogue processor is Stonehenge and other stone circles. It comprises a bit of hardware (the stones) which has an input (the sun) shining through an aperture to cast a shadow (the output) which indicates the mid winter sun. It has an iterative program, where someone checks each day to see how far the shadow is from the midwinter marker. It is one of the finest examples of Ubiquitous computing because it is a processor which sits in the background doing it's main function, but the builders of Stonehenge had no idea they had built a processor.