F-line to Dudley via Park wrote:
I get that it's a fairly minor thing, but it says right there in the T page I linked to "full replacement of the steel superstructure swing span", and then rehabilitation of the existing approach spans. That sounds to me like a replacement of the swing span using the existing approaches. Unless you know more than is on the website?
deathtopumpkins wrote:Speaking of improvements to the Eastern Route, I found this on the T website, which is either new or I hadn't noticed before:
It's not a replacement. "Moderate" in-place rehab for not-large money, which is why it hasn't drawn a lot of public attention. Has been programmed in the budget for years now.
http://www.mbta.com/about_the_mbta/t_pr ... 6442452879" onclick="window.open(this.href);return false;
Final design for the first phase of replacing Beverly Draw was apparently supposed to be finished in November. Has anyone heard anything about this? Will the replacement span allow higher speeds?
Will improve reliability of the swing a good deal by doing overdue replacement of the worn-out machinery and parts of the superstructure most likely to get stuck. Approach span work fixes some longstanding problems with the decayed pilings. But it's nowhere near the same universe as the megabucks "like-new" rebuild of the Merrimack span in Haverhill. This falls more in the line of cycled rehab that has to be done about once every 2 decades to a movable span of this advanced age to keep it in non-deficient working condition, whereas the Haverhill megaproject is fully rolling back the clock to a whole new 'rebooted' 75-year rated lifespan.
The approaches are just pier work...stuff that probably hasn't been touched since the thing was first built. From what's been described in ancient threads here that's all below-deck work done off barges with those temp drydock structures for accessing below the water level. Other than maybe speed restrictions to reduce load on the piers during the most critical phases that whole Phase I shouldn't affect train service or cause track outages at all. Based on what I Googled from old local news articles this project has been in agonizingly slow planning for 10 years now and the North Shore has been barking to the T about lack of progress on it since at least 2008.
The swing span isn't getting a full and complete replacement like, say, a couple of the Amtrak Shoreline bridges in CT (Thames River, etc.) got their bascules totally ripped out and replaced by cleanroomed lift spans fitted to the existing approaches. It's a moving parts renewal and rail deck replacement, but the structure including the actual physical swing aren't being touched and will still be 'original' condition. Project's all limited to stuff that has to be normally cycled every few decades on a frequently-used moving span no matter what its age. I'm not even sure the swing mechanism got much in the way of touch-up during the 1985 repairs after that severe 1984 fire on the approach span severed commuter rail for a year, so the relative invasiveness of the swing rehab is cycled renewal + pulling out of a deep deferred maintenance pit because they haven't been doing cycled component renewal anywhere near as often as they should've.