mikejuk writes: A computer conservation project to build a working replica of one of the first general purpose computers has reached an important milestone. Work has now begun on manufacturing the huge steel chassis required to replicate EDSAC as it was in 1949. Originally announced twelve months ago, (http://hardware.slashdot.org/story/11/01/14/0248203/edsac-computer-to-be-rebuilt) the project to rebuild the Electronic Delay Storage Automatic Calculator is on schedule for completion in 2015. There are few original components since when EDSAC was scrapped in the late 1950s only three of its 140 chassis survived. It is one of these that is being as the model for the production of the first 20 replica chassis at Teversham Engineering Ltd in Cambridge. Not everything about the rebuild is going to be authentic however. Health and Safety considerations have replaced the mercury delay lines with nickel versions which are less poisonous.