Here’s a variant Boston MBTA map I’ve never seen before: a version with 60-degree angled lines, instead of 45 degrees. Apart from that, it looks very much like the standard late-1960s/early 1970s Cambridge 7 spider map, although there’s some weird inconsistencies like the Green Line “A” Watertown branch (closed 1968) and Quincy Center (opened 1971) on the same map.

Here’s the interesting part. This map lives in the one and only mock-up of an MBTA “Type 6” train carriage at the Seashore Trolley Museum in Kennebunkport, Maine. This wooden mock-up was created in 1968 by MBTA engineers to allow stakeholders and the public to judge the design’s layout and comfort, but the carriage was eventually deemed too expensive to produce. The MBTA ended up procuring the (incredibly unreliable) Boeing-Vertol LRTs instead. So… this map may actually be as unique as the mock-up that houses it: the only one of its kind. If anyone knows anything more about this variant, I’d love to hear about it!

Source: Eric Kilby/Flickr – thanks to Boston to a T for further info on the mock-up