There were a couple of bad derailments at the beginning of double track (eastbound) at South Acton. Detours went via the Stony Brook Branch and Lowell. One was in December 1970. It happened early in the morning and some Budds were trapped at South Acton. They were retrieved by a crew using the Ayer Budds and coming through a siding by the South Acton freight house, bringing them to Willows, then the whole outfit ran via Lowell to Boston. This was a very bad period. While clean-up work was going on at South Acton with 120-ton wrecker (Boston) and 250-ton wrecker (E. Dfld) working from both sides of the wreck, a freight piled up at Wachusett and some cars damaged a trackside industrial building. East-west main was thoroughly tied up. A second detour was set up Gardner-Barber-Ayer-Lowell and then either Boston or Rigby. Clean-up at South Acton was delayed as 250-ton wrecker and 200-ton (McVille) were sent to Wachusett. The Berlin job derailed at Bath, NH and that couldn't be cleared as all resources were at South Acton and Wachusett. Then Christmas came. All the clean-up crews got a few days off. When they returned to work, all three wrecks were cleaned up and the lines restored rather quickly. When I started with the B & M in 1968, Gardner-Barber was still served by WM-1/MW-2 but they had been discontinued by this time and the branch was virtually dormant. This was the only time I knew of any detours on this route.