SN13 Recollections By Charles Clark

From: Charles Clark <*******>

Subject: Re: Meeting on 7th October

Date: 3 January 2022 at 16:15:48 GMT

To: DCLaufer <davidl@*******>

Cc: Clive England <clive@********>


Clive just sent me the recording of our virtual visit to the CMoA in October and since you talked again about  S/N 13, your Cray 1 from Max Planck, I am reminded of another story that may be of interest.  As you probably know customers ordered Cray 1s and then waited for 9 months to a year while their system  was built and checked out in Chippewa (sometimes they got an older system as an interim but either way it was a computer manufacturer’s dream to have customers lined up and willing to wait).  Anyway these systems were checked out in parallel in separate bays in Chippewa manufacturing and someone (I don’t know who) made an appropriate model to sit on top of the system while it was being checked out in System  Test. These were made out of wood (or they were a country flag if the customer was in a new country to Cray). I don’t  remember all the models but I remember a little carved airplane sat atop the S/N 14 for the Air force Weapons Lab and  much more to the point I remember the model carved for S/N 13 destined for IPP in Garching, which I helped to install.  You will know that computer room raised floors were usually made from 2′ x 2′  tiles on a grid and supported by  pedestals at each corner of the tile.  Needless to say with the concentrated weight of a Cray 1 extra pedestals were  placed at designated positions under the Cray to support the weight (You probably did this in the Museum too even though you mentioned that your S/N 13 is no longer fully populated). 

Well the raised floor at IPP was quite different; it was suspended on beams over a 10 to 12 foot cellar. Cray’s installation  planning team requested that the customer build a concrete cube below the Cray so the required extra pedestals could be placed and the weight distributed as usual. The story of the “special” installation reached Chippewa and so the model carved for the system checkout bay was a “Sky Hook” to “support” the Cray on site just in case the floor gave way.  This model was duly packed with all the equipment when the system shipped to Germany and I placed it atop the system for a photo (see attached). I am pleased to say the concrete cube work around worked well and the Sky hook was never  needed!! Although while installing the other equipment like disks etc one had to be careful when they raised the other floor tiles because, apart from where the Cray was, it was a long drop to the floor of the cellar.  When you look at the picture you will note that S/N 13 shipped with the classic Cray 1 panels (Blue /Green/Red) so I am not sure when the yellow skins were fitted. Perhaps that was done at the “Jim Curry’s Cray museum” that I believe the system went to before it shipped to you.  

Just thought you would like to know just how much personal attention the Cray 1 systems had while they were being checked out for each customer.:1

Best Regards




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