This post originally appeared on Orphan Road.
…and it’s far too late anyway. But what if instead of light rail over I-90, we just connected downtown Bellevue and downtown Seattle via gondola?
The two are just 6 miles apart. Yes, that’s huge for gondola distances. And over some deep water. But I feel like crunching some numbers, so humor me.
Speed
We’d definately want to use 3S technology – that’s two support cables and one drive cable. This would allow us to go 24 mph. So that would be a 15 minute journey. Hey, that’s much faster than Link’s 20 minute journey! Of course, South Bellevue station and Mercer Island would increase in travel time, but everything north of Bellevue won’t be affected much (transfer will surely take less than 5 minutes, when a car leaves every 30 seconds).
Capacity
So a gondola would win in terms of speed. What about capacity? East Link will have a maximum of 4-car trains every 8 minutes going to the east side. If each car can hold 200 people, that’s 6,000 people per hour per direction. But wait, Whistler’s 3S system can carry 4,100 people per hour per direction. And with larger stations we could add more cars, bringing that number up.
Cost
This is the big unknown. Gondola systems are cheap compared to light rail systems, but keep in mind we’re really only comparing the section of light rail crossing I-90 (though this is probably an expensive stretch of rail). We would need to keep the rest of the planned system, even adding a storage and maintenance area, because East Link will serve much more than Bellevue. Also, we’d be crossing a deep lake. I have no idea how much towers going down 200′ to the floor of Lake Washington would cost, but I’m quite sure it wouldn’t be cheap (there’s a reason we use floating bridges around here). We could have high towers on either side and skip mid-lake towers (the lake is only 2 miles across), but that could be expensive too.
Thoughts
Well, I’m a day late and a dollar short on this one. Our entire region’s already agreed on a plan, and it’s likely a better plan than mine. Plus leaving the east side light rail disconnected from the west side light rail system kills all kinds of efficiencies. Then again, maybe I’m not thinking big enough. Why not branch out from Bellevue with gondolas?
The depth problem would make it very difficult, technically, but crazier things have been done.
I think the biggest problem is going to be getting people on & off. Link’s 6000 person-per-hour capacity is based off of people getting on & off at different points. A gondola might be limited in the # of stations it can support.
I think that as a supplement (such as Portland’s river crossing), or for short lines where buses/rail can’t go (Westlake -> top of Queen Anne, or perhaps QA -> Capitol Hill, gondolas would be perfect.
Now, what I’d like to see, rather than rail-along-520, is a new rail-only bridge connecting Ballard to Kirkland, via the U-district & sand point. This is the narrowest point of the lake, and connects cities, whereas 520 carefully avoids the cities.
Good point about moving people on and off. However, keep in mind that people aren’t arriving in 8-minute slugs, they’re loading and unloading several times a minute. 6000 people per hour per direction = 100 people per minute. That’s still a large number of people, but not the 1,600 people that could get off a single 4-car train – even if only a quarter get off at any one station that’s 400 people.
Of course another solution would be using gondolas for the entire east side network.