Slashdot Mirror
1935 Meccano "Dam Busters" Computer Restored
rob1959 writes "A 1935 analog computer, built at Cambridge University and used to help plan the Dam Busters attacks on the Ruhr hydro dams in World War II, has been restored and put on display at Auckland's Museum of Transport and Technology. The computer came to NZ around 1950 and was used, ironically, to build hydro dams there — and to calculate rabbit population numbers."
gR4NP4 W45 4 l337 H4x0R, 0Wn3d 7H023 N421 m0F05 l0L.
Would of thought they needed the sheep population controlled more than the rabbits...
Imagine a beowulf cluster of these!
That people here understand Irony unlike fark.
TFA also mentions the recent sad death of Donald Michie - a major force in early British computing. I had the honour of working with him on 'Freddy' the robot back in 1973 - back when the UK led the world in robotics.
init 11 - for when you need that edge.
I'd heard of the famous skipping bombs, and knew basically how they worked. But I'd never heard of http://en.wikipedia.org/wiki/Operation_Chastise, nor the book (or movie) "The Dam Busters". Additionally, it seems that Robert Jackson will produce a remake of the 1954 movie. Most fascinating to me, though, is this Meccano computer. Those engineers were brilliant.
Jeeze, thank god computers got smaller. That thing wouldn't fit in my lounge...let alone my bedroom
ilovegeorgebush
In fact it was last really used in anger to build a remote control to perform a one off dangerous operation safely, and its loss probably cost the company a lot of money when POC models had to be engineered expensively by local contractors instead of being built quickly and cheaply by an engineer in house.
So RIP real Meccano. Doing FEA on a workstation just isn't the same as using an analog computer.
Pining for the fjords
Operation Chastise did not have the military effect that was at the time believed. By 27 June, full water output was restored, thanks to an emergency pumping scheme inaugurated only the previous year, and the electricity grid was again producing power at full capacity. The raid proved to be costly in lives (more than half the lives lost belonging to allied POWs), but in fact no more than a minor inconvenience to the Ruhr's industrial output.
In his book Inside the Third Reich, Albert Speer expressed puzzlement at the raids; destruction of one of the dams served no purpose at all, he claimed, and the failure to follow up with additional raids represented a major lost opportunity for the Allies.
Slashdot: providing anti-social weirdos a soapbox, since 1997.
you expect to occupy a room in the mansions of guys like Gates, Allen, and Ellison. You know, to emphasize that they are computer guys.
A 275 pp pulp I got at a precocious age still devoted a significant percentage to analog. But, then, 5 years later Pickering was still offering high school classes bulk rates on slide rules.
does it run Linux???
Readers interested in this item may find the recent episode of Mystery "Foyle's War: Casulties of War" adds to their understanding:. html#casualties
http://www.pbs.org/wgbh/mystery/foyleswar/series4
Great period series and this episode has specific ties to the topic at hand.
I built a 1/3 scale copy of one of these in my bedroom with my erector set in the 60's on a piece of plywood. I could have taken over the world then but my snotty sister turned me in.
And I don't know how to format comments. [cue Price is Right loser music] Wah Wah Wah Wah Waaahhhhh
It's a type of Parrot you dolt
I'm 41 and my *father* WAS in WWII. He was born in 1921, and was 44 when I came along.
Before you design for reuse, make sure to design it for use.
The rabbit population metrics were actually being used to determine how many rabbits it would take to destroy a dam. The dams the computer was used to build were just intended to be targets.
"It is a miracle that curiosity survives formal education." -Albert Einstein
Did anyone think this was going to be about a Meccano toy set? I was thinking to myself "A meccano toy set that's a computer!? Wow that's a helluva kid's construction toy!".
If they would only employ the Utopian method of raising rabbits they would have no need for such a computer...
Tactically, the dam raid did not cause the catastrophic industrial disruption which had been hoped for, and the lack of a follow-up raid to suppress repairs meant that the Germans could recover. But strategically, Wikki has this to say:
" The strategic view
The Dams Raid was, like many British air raids, undertaken with a view to the need to keep drawing German defensive effort back into Germany and away from actual and potential theatres of ground war, a policy which culminated in the Berlin raids of the winter of 1943-44. In May 1943 this meant keeping the Luftwaffe and anti-aircraft defence forces' effort away from the Soviet Union; in early 1944, it meant clearing the way for the aerial side of the forthcoming Operation Overlord.
By far the greatest and most unexpected effect was on German food production. The Ruhr valley below the dams was a major source of vital food for Germany, and large areas of arable land were rendered unusable and huge numbers of farm animals were killed. This had an immediate negative effect on German morale. In addition, the pictures of the broken dams proved to be a morale boost to the Allies, especially to the British, still suffering under German bombing."
And of course, a major effect was to pursuade Harris to support Barnes Wallis's greatest contribution, the Tallboy and Grand Slam supersonic precision earth penetrators. These stopped the V2 and the V3, and sunk the Tirpitz, and well as the U-Boat pens at St Nazaire. The Americans wished they had something like them, and are only now developing something similar for use against Iran.
... a Beowolf Cluster of These!
Did Churchill come to power in equally suspect manners?
Blar.
No Linux, but there is a build of NetBSD for it.
I drank what? -- Socrates
I am also 41 and my grandfather fought in WW1
I think this seems to show, at least in some cases, the generation gap may be increasing.
If you want to see a short clip (in color) of one of those devices in action, watch the George Pal version of "When Worlds Collide." (1951) In the script, one is used to verify the trajectory of the approaching planet.
Afaik, they were released so they would bounce towards the dam, be stopped by hitting it, then sink to a certain depth before detonating.
WORST. TROLL. EVER.
The entry for Bouncing Bomb has a helpful animated illustration. And, of course, the entry for Operation Chastise is head and shoulders above the site that TFA links to.
The "cue the foo posts in 3, 2, 1..." posts will commence with no subsequent foo posts in 3, 2, 1...
A, the raid was the first major blow the allies, especially england, managed to land againt the seeminly invincible germans. The raid proved that the germans could be hit, and deep inside their own country too. Morale matters, ask the americans about it sometime.(Vietnam, current conflict)
B, it forced german forces to be relocated inland to defend other possible targets from air attack. Every piece of equipment and soldier NOT at the front meant german fighting power was reduced.
C, the damage had to be repaired and this took precious resources the german never had enough off.
D, you are taking the word of a nazi about how effective an allied action was? Why don't we ask Microsoft for the their honest review of the PS3 next?
E, this one is a bit more complex and requires you to think for a bit, something I doubt you are capable off.
German war production was on the rise. Lets say at the start of the year I have a car factory that produces 1000 cars each month. BUT I am also increasing production every month by 100 cars. So by the end of the year I should be producing 2200 cars right?
Okay, now you bomb that in may (production has rissen to 1500 cars) factory. I am out of action for say a mere 2 months. I then claim that I august am producing the same number of cars as before the bombing, namely 15 cars.
AH, all is well right?
Not exactly, first I am missing the production of june/juli 1600 and 1700 cars PLUS I should have product 1800 cars in augustus, NOT 1500.
The statement "back to pre-XXXXX levels" is a standard piece of mis-information that the stupid, like you, always fall for.
What counts is what wasn't produced during that period and how much it has slowed the growth of the economy.
This kind of devices were used to calculate differential equations using hydro-mechanical analogues of differentiators and integrators. Basically, this sort of calculating machine would be easiest implemented today, using operational amplifiers and discrete components such as resistors and capacitors (or even inductances).
To be honest, in 1935 there were electronic tubes, and such a machine could have been implemented with them, therefore electronically. But probably the complexity and low reliability of electronic tubes of the time had rendered it unviable.
"The agriculture ministry is not in charge of Gundam" - Japanese ministry official.
Fantastic troll there. Seriously good. You touched on the whole dumb-americans-using-films-as-history-textbooks, perceived American military supremacy, Britain being shit, and "us" vs. "them". Very well-rounded troll. Excellent work.
"However, the only original, complete Differential Analyser left in the world happens to be the one that helped Barnes Wallis design his famous bouncing bombs."
In that case, what is the one that is in the Science Museum, London?
Maybe the poster was thinking of the MYTH Buster guys.
The Dams Raid was, like many British air raids, basically base camping to keep the uber-GER clan from capping flags and holding the helo spawn point. Though the RUS clan was previously unimpressed, it let them get four levels higher on the PWNAGE ladder. Three BRIT-"lol-nub" team tipped the scales and made some righteous Fraps vids for Youtube.
Don't forget the 'US ignorance' (little rubber bouncing incendiaries!) and complete unwillingness to actually read the indicated post!
Seriously, though, the US completely ignored earthquake bomb technology for over 60 years, because it 'wasn't invented here'. Then, when they needed it against Iraq/Iran, no one knew anything about it! They are now busy re-inventing it as an American weapon.
That would indeed be some funky turnaround in history.
WILL IT BLEND?
Dana Carvey as The Geezer: Back in my day, we deedn't need no steenking dij-it-al compootors. No, you plugged the wires and gears together, tied it up with string, and let it run smoking for six days just to add three plus seven. The smoke filled the room, you choked, and died, and you liked it!
(-1: Post disagrees with my already-settled worldview) is not a valid mod option.
Got to love wikipedian NPOV. From the aforelinked Bouncing Bomb page:
After Operation Chastise, the Germans discovered an Upkeep bomb that had failed to explode lying in some woods and subsequently a 385 kg (850 pound) version of the bouncing bomb was also trialed by the Luftwaffe. Designed for use against British shipping, it was given the codename Kurt, and was built at the Luftwaffe Experimental Centre in Travemünde. Not being a cricket playing nation, they failed to understand the importance of backspin, and in trials, dropped by an Fw 190 it proved to be dangerous to the delivering planes as the bomb matched the speed at which it was dropped.
Leben Sie jetzt die Fragen.
I know you are trolling - but one of the WWII documentaries that run on N24 all the time mentions the bombing of the Möhnetalsperre, including allied (color!) video footage of the devastation.
Want to hear the voice of GOD? cat
These old "analog" computers are really cool. The Communications of the ACM 60th anniversary retrospective issue from a few months ago talked about how the computing machinery field was once divided between people who wanted to build machines to do continuous computation and those who favored the discrete route. As computational machinery moved toward the discrete route, there were even "hybrid" machines where the digital side controlled an analog side. Of course, as TFA points out, these differential analyzers were not "programmable" in the modern sense. Interesting stuff-- makes you think about what kinds of tradeoffs we make to go with our current digital designs.
The bomb skipped across the water until it HIT the dam.
f t/The%20Bouncing%20Bomb.htm
The bomb then bounced back, and started to fall. During the fall the backspin made it move forward again, right up to the dam face.
The bomb fell approximately half-way down the dam - further than illustrated!
The above points are critical - Wallis found that explosive needed to be placed RIGHT AGAINST the dam wall to work effectively. It is probable that the several bombs used on the Mohne which did not break it initially were not centrally placed and failed to stick to the dam face.
A much better illustration is here: http://www.chm.bris.ac.uk/webprojects2001/moorcra
What the animation didn't show is that the bombs had to be spun up counter clockwise before they were dropped, to get them to bounce on the water. The Lancaster bombers had their bomb bays modified with the mechanism to do this, basically a giant chain and sprocket. Just think about skipping flat rocks on the water, the more spin the more bounces.
Unsurprising as they run counter to common historical opinion - which is that the raids accomplished little of lasting importance. In particular the conclusion about the effect of the Dambuster's raid on AA is nonsense because a) the dams and other important industrial targets were already protected by AA, and b) the raids on German cities were already drawing AA away from the Eastern Front. (As well as diverting considerable industrial effort to increased fighter production.)
This specifically is an impossibility - pictures of the damage to the dams were classified and not released until postwar.
This paragraph can best be described as hyperbole... Niether the V2 or the V3 was stopped until the installations were overrun by the Allies. The St Nazaire U-boat pens were never attacked by such weapons and remain intact today. Sinking Tirpitz... Well, by that point in the war attacking her had become a habit. In reality Churchill's ongoing focus on her destruction consumed man hours and resources all our of proportion to her remaining strategic importance.
And now we come to the real reason for your post and the fictions it contains:
You wish to sneak in a slam against the Americans... And just like the above, you get your facts wrong.
Dad was a Korean war vet, and I fell into the notch between the Viet Nam and Persian Gulf pseudo-wars.
--Charlie, posting anon from the beach
In the early '80s, I bought a used, rack-mounted electronic device. I also got some
analog multipliers along with them.
I took it to work where they had oscilloscopes I could use. One of the owners
of the company recognized what it was and told me it was an analog computer.
It had op-amp boards in it with a power backplane (you need +15 and -15 volts plus ground
for example). On the end of each board was a row of holes connected to various inputs
and outputs on the board.
There were other boards with nails coming out of them, that you could solder together
to make a "program". So you could switch from one program to another by pulling
out all the boards with nails and wires, re-arranging the op-amp boards, and putting in a different
set of boards with nails and wires.
I was in college at the time and they guy who explained how it all worked was
Ro Favreau. He had worked with analog computers for solving artillery
trajectory problems.
I remember fondly talking to him about it all and learning. I hope I will be able to pass on something I've learned over the years to some young man or woman engineer.
"We can't solve problems by using the same kind of thinking we used when we created them." -- Albert Einstein
"The Americans wished they had something like them, and are only now developing something similar for use against Iran."
Incorrect, the Americans had a copy of the Grand Slam just before the end of the war, and you could argue that the US has led the field in super bombs if you include nuclear weapons (nuclear weapons replaced the roles carried out by tallboy and grand slam). Large conventional weapons are typically used more for psychological effects. To the average observer, they look like tactical nuclear weapons. Cue radiation scare.
How is the NZ government going to continue to function now? Surely 80% of our computing power is now sitting in a musuem! (The rest is owned by Weta)
Umm. Our earlier friend had several facts wrong, but then again, so do you.
1 - AA and air defence - the level this is kept at is continuously assessed. A raid like Chastise would have certainly had the effect of keeping German Home defence higher than it would otherwise have been.
2 - The V2 factory at Eperlecques La Coupole was ruined by earth penetrators - this certainly limited the numbers of V2s which could be released. The V3 weapon was completely destroyed by earth penetrators before it could fire a shot - you are completely wrong to say that it was stopped by ground troops.
3 - the St Nazaire pens were indeed never attacked by Tallboys. The Brest pens were, and were penetrated. I suspect our earlier friend has mistaken the two.
4 - the Tirpitz was continuously attacked because she needed to be taken out, and the Navy couldn't completely sink her. She was regularly damaged instead, which kept her out of the game. It would have been the height of foolishness to have left a major battleship, stronger than any Allied unit, intact. The Tallboys and Grand Slams proved very effective against her.
5 - Once this weapon was developed the Americans indeed wished they had something like it. They developed a similar, but heavier bomb using the same principles, and then found they could hardly get it into the air! Then they forgot about the principle during the Cold War, and needed to develop things fast during the Iraqi war!
The Paveway bombs you reference are NOT earthquake bombs. They lack the penetrative ability - the only strengthened one you reference contains 600lb of explosive. These are bombs intended to be dropped ON the target, not some way to the side and under it. You do not seem to understand the concept of an Earthquake bomb. I suggest that you read Barnes Wallis's original papers on the subject - I am sure there is a copy of 'A note on a Method of attacking the Axis Powers' on the net somewhere.
I would say that a good many of the original comments are still valid - and your last comments show that Americans STILL do not understand how these weapons are designed and used.
Wouldn't a torpedo used to sink a ship been more effective?
Oh, dear.....
1) The US indeed did a copy of the Grand Slam. They made it bigger, and then found they could hardly lift it with the aircraft they had!
2) Of course, the British assumed that they, together with the US, led the world with nuclear weapons technology. The bomb development had been a joint effort, after all. But then the US reneged on the information exchange deal.
3) The Americans have a child-like mentality, and admire bigger bangs. Earthquake bombs are NOT about bigger bangs or psychological effects. That is why tactical nuclear bombs are NOT a substitute for earthquake bombs, and bombs like MOAB show the US love of wasting power in a childish gesture. This last comment really shows that Barnes Wallis's theories are not understood by the US, which is why, even now, they do not have an earthquake bomb, or any idea about how to use one in combat.
I was working for the central UK Govenment IT Security Authority when the Babbage machine was completed. You will recall that the original was commissioned in the 1840s with UK Govenment money, but never completed.
During the period 1840-1990 computers became a commonplace tool for govenment work, and various standards had been set for their acceptability. One of these was a requirement to incorporate appropriate security countermeasures. Since we were a technical computing part of the UK government, we were invited to the unveiling party for this machine.
In preparation for this we decided, as a joke, to consider accepting the system acording to the original specification. I was doing part of the risk analysis, and, working off a copy of the schematic plan, noted that the mode of operation required the operator to set the input data wheels, and then turn the calculation handle a requisite number of times to complete the calculation.
The first risk we identified was that the operator might miscount the number of turns. Babbage had addressed this by providing a counter wheel which documented this number in real time. Acceptable countermeasure.
There was a second-order risk that the operator (getting tired after winding the handle in excess of 1000 times) might notice that the counter wheel could be reset to advance the apparent number of turns. We raised this as a possible concern, and brought out paper to the party.
To our surprise the curator's face lit up. 'So that's what it's for!', he said, and brought us over to the brass tower of gearwheels. He showed us a little lip, set into all the counter wheels, the function of which had not been understood before. Now it was obvious that it was intended to prevent alteration of the relative position of the counter wheel set once a calculation had started. If you tried to move the counter wheels half-way through a calculation they would jam.
We were happy to alter the paper there and then, and certify the Babbage machine as passing its security audit for acceptability for Government service. It may have taken 150 years, but we got there in the end!
It would have been if the Germans were stupid enough to forget to put torpedo nets in front of the dams.
However, they were not foolish, and did put torpedo countemeasures in.