First apologies for the follow up post, I don’t think I can easily fit everything into comments to the original thread. I got some great comments from, Al S, AJ and William C, and Guy on Beacon Hill did some field work downtown! The most pressing question I think is about turn radius. I had envisioned going above, or if necessary taking the small, 60s office building at the corner of 5th and Union (or above the Banana Republic for Pike), but Guy was right, that would still be too tight. While I couldn’t get find the original ALWEG turn radius, the Malaysian trains, which are very similar, have a minimum radius of 70 meters. Not enough for the 5th and Union turn. Should have double checked. However, that lead me to a slightly different alignment which might actually be better in terms of competing with fewer views and presents a rather unique opportunity to leverage a second stranded asset.
Abandon Westlake. The station would have to be rebuilt anyway to make better connections with Link and to fix the unfortunate pinch point where they narrowed the guideways when they built the new station in 88.
Instead turn from 5th on to Olive. This would require going above McGraw Park and the two story BofA building and/or taking it (possibly to create a new station.) This would still offer nice connections to Link and the expanding streetcar system. This would yield a turn radius of 110 meters.
From Olive the line could utilize the space above I-5 to turn to reach either Pine to reach further into Capitol Hill (option A) for an east running route or Boren (option B) to reach the hospitals on First Hill. Again, I think this alignment leave room for the turn.
The Pine street alignment could reach further into Capitol Hill with a stop perhaps at Pine, 16th and Madison where the 7-11 is. From there, it could be extended as far east to 23rd and the down 23rd all the way to the I-90 stop or even Mt. Baker. The turn from Pine to 23rd could be above the City Light marshalling yard, which should yield sufficient radius. Running the line to the I-90 station would be 5.3 kilometers.
Alternatively, the Boren route, suggested by William C would better serve the hospitals and the redeveloped Yesler Terrace. Possible station location could be in the parking lot at Seneca and Boren, or the parking lot at James and Boren. This route, too could be extended all the way to I-90 or Mt. Baker without and a single sharp turn. The Boren route to I-90 would be 4 kilometer. Both extended alignments are here.
Finally, there is the prospect of building a station as part of the Convention Center expansion on the site of the former Convention Place Bus station. First, it would be in the Convention Center’s interest to have a station. Second the city has some leverage now in the permitting stage, especially as the WSCC and the developers want to vacate Terry. Finally, the WSCC has some commitments to Metro as part of the purchase agreement to sustain bus access for a period of time. Perhaps that could be traded for a monorail station? Personally, I think having the Monorail running inside a glass tube above the main exhibition hall would be cool, but there’s obviously a number of way to incorporate the station. Perhaps the abandoned bus tunnel from Convention Place to Westlake could be turned into moving walkways? Perhaps having its own monorail line would reduce the need for parking?
Again thanks for all the great suggestions. Where is the more pressing need, First Hill, or going as far east as possible? Best station locations?