I was curious with the maintenance Sound Transit was doing the week before the pre-Thanksgiving snow storm, so I went for a field check. The Rider Alert said southbound platforms at Mount Baker and Beacon Hill would be closed, telling me the general area of work. I arrived at MLK and Walden around midnight, where there is a crossover for trains to switch tracks, and saw the red STOP sign and flasher on the southbound track indicating “men at work”. I saw no visible activity outside, suggesting the work was being done in the Beacon Hill tunnel. Later, someone commented on the blog that the work was about fixing leaks on the southbound platform of Beacon Hill Station.
Sound Transit spokesperson Bruce Gray confirmed to me that the work was indeed about fixing the leaky tunnel. The work is covered under warranty, which means the contractor, Obayashi, is responsible for the costs of fixing the defect. Beacon Hill Blog has photos and a report from September that quoted Gray saying such leakage is common in the first year for deep-mined projects. I visited Beacon Hill recently and saw the drainage system they installed in an attempt to collect the water and prevent it from dripping. It was still dripping though not as much as it used to. Fortunately, once this issue is resolved, Gray said “this should be the last of these maintenance delays during revenue hours for a long time.”
Past engineering and maintenance work on Central Link during revenue hours include noise reduction work with rail grinding in Rainier Valley and Tukwila, modifying crossovers on MLK to reduce noise, installation of track lubricators at Mount Baker and Tukwila; installing switch heaters by the Operations and Maintenance Facility to keep trains running during snow and ice conditions; and a weekend closure of the Downtown Seattle Transit Tunnel for upgrades and testing of the fire/life/safety systems.
I remember the DSTT used to have a lot of leaks, especially at Westlake.
I’m not trying to be snarky here, just curious. Why do you need to limit the trains system-wide when work is being done in one station? Does the work area extend to the tracks?
They have to shut down power to the 1500V overhead wire in that section they are working on. As the photos show, the ring of water encircles the tunnel so for safety.
To add to that, they ALWAYS have to shut off the OCS when doing any serious work. When I went out with a track gang in July 2009, the OCS had to be shut off and shunted to the rail with a special copper pole that clamps to the OCS (positive) and rail (negative), even though we were nowhere near the OCS.
Interestingly, it’s an hour-long process to power down and turn on the OCS. Lots of steps and safety protocol to be followed. And I think the switches have to be locked out as well.
It seems a little excessive to shut off the OCS for simple track work. It makes sense if things like ladders or cranes are being used, but simple work at track level shouldn’t require that. In fact, in the 50s, minor track adjustments were done with the power still on to the third and fourth rails, and track workers were instructed not to stick their shovels between the running rail and the positive rail to avoid shorts. And assuming the track gang already has a track possession, getting the power shut off should be a matter of calling the power controller, asking him to trip the relevant breaker, confirming that the power is off, and then installing the shorting device. All told that should take something like five minutes.
And there aren’t switch over between each station, so a large area than just that station are also affected.
There is limited capacity when running bi-directionally on only one track. The trains have to cross over at O&M and south of Mt. Baker Station. Speeds are limited through the crossovers, and typically on single-track running as well. Since it normally takes about 6 minutes to go from O&M to MTB, and an extra safety minute, there can only be a train every 7 or so minutes. So, with slowdowns, we’ll say 20 minutes between trains in each direction.
Indeed. Thank goodness the tunnel was built double-tracked instead of single-tracked as was once proposed!
Ah, so a lot of these maintenance closures are just related to the newness of the system and correcting known construction issues.
No big deal then. Things should get better with time (not that things have actually been that bad so far).
Nice.
I’ll be glad when they can stop the water drippage and mineral stains on the side walls. No stalactites in my station, please!
You should’ve seen the icicles by Convention Place station!
Speaking of the Convention Center and leaks, I am sure you are all aware of the leak on I-5 when you pass under the convention center going northbound as you come out of the tunnel. Hasn’t that part of the center been built for 20 years and they still can’t fix that leak…on the freeway?
Amazing they can fix the leak in the light rail tunnel in a year but the one on the freeway just keeps dripping and dripping and dripping…
Haha, station stalactites. Reminds me of New York… even the highest-traffic stations like 34th St-Penn Station.
Beats me why they can only run service every 30-45 minutes when:
1. travel time between SODO and Columbia City is 8 minutes (dwell included), between the crossovers at OMF and Walden 1-2 minutes less.
2. meaning a train should not have to wait more than 8 minutes to get on the single track section
3. meaning 15 minute service should be possible with minimal delays to passengers when timed right
4. therefore a schedule can be published for abnormal events like this
Many passenger rail systems can operate 15 minute service with a single track and I think that was the idea when they designed Link. Is there some kind of contractual inflexibility with schedules or don’t they have the capability to quickly develop a special schedule for such events?
Yeah I agree. In the rail economics and planning class I took in Sweden we learned how to make schedules, and specifically how to schedule single track operations. I could probably throw together an excel schedule for link in a few hours. It really isn’t that hard. Actually if I have time tonight I’ll try to do it.
One additional consideration is men on the adjacent track. The trains may be operating bi-directionally on a single track, but if the workers have to stop work to move every 7-10 minutes for a whole minute, not a lot of work gets done. That being said, it’s in a divided tunnel, but they might be following general Sound Transit safety procedures.
With safety time built into switching and crossing over, realistically its about 10 minutes between trains.
That’s a fair question about getting a schedule out when we have these extended delays in any block of time. We’re working on getting one together and hope to have it out before tomorrow night’s work. Unfortunately won’t have it in time for the work tonight. Stay tuned.
Bruce Gray – Sound Transit
I don’t mean to sound repetitive, but might it be possible to run overnight service for special occasions (e.g. Christmas and New Year’s Day), or maybe even Friday and Saturday nights? — using a single-track plan if necessary?