Patrick Ford had a ringside seat to watch the plus-sized 39 buses shimmying all over South Huntington Avenue in the snow, because they never seem to remember that they just don't do well in the snow there.
Good. As a rider of the 39 since the 80s I love this. 1. Keeps other vehicles out of my swerving way resulting in a winning lead, and 2. I finally get my fare's worth by feeling like I'm on an amusement park ride. The 39 Masshole!
The T is buying functionally-identical (60' New Flyer hybrid) buses as replacements for the Silver Line Transitway buses.
We'll truly have a world-class transportation system when the new buses struggle to climb up the many highway entry/exit ramps around the airport. Those roads might be better plowed, but they're also steeper and have much less physical room for error. How does "no SL1/SL3 service during inclement weather" sound?
Most of the articulated buses (the 2010 and 2016 models that run on the 28, the 39, and the SL4/SL5) have the front two wheels (right near the articulation, or the "bendy joint") powered, but the rear two wheels are not. Hence, the T has to replace buses on those routes with regular 40 foot buses during the winter to avoid the longer buses from fishtailing.
Anything that runs in the Silver Line tunnel (SL1, SL2, SL3 and Silver Line Way) has rear axle power due to the grade of the Silver Line tunnel: the original buses delivered in 2004 that operate on electric power in the tunnel and diesel power on the surface, the bus delivered with extended battery power in 2019 (and the upcoming 45 bus order replacing the 2004 models in 2022), and the four fully electric buses also delivered in 2019.
in the Transitway, I can confirm that the T only runs the 60-foot buses on SL1, SL2 and SL3. (There once was an experiment when the T ran some trackless-trolley type 45-footer just in electrified territory of the Transitway on the SLW, but it didn't last long).
In the winter, the T will occasionally detour the SL2 around Black Falcon and the Design Center due to snow, but I am unaware of any other restrictions on the SL1 and SL3.
When the Silver Line tunnel originally opened, there were 40 foot trackless trolleys that operated to Silver Line Way until the 60 foot dual-modes were accepted into service. Those trackless trolleys were transferred to Harvard Tunnel service soon after.
I've updated my original post.
I think you have it backwards. How would a bus with its diesel engine in the rear section have powered wheels in the front section? A driveshaft can’t bend.
... what universal joints and differentials are for in drivetrains. It's entirely possible to do what you mention above, engine in the end, driving wheels in the middle. The engine sure isn't in the middle of those buses, and pushing from the rear articulated section would result in some very strange handling characteristics.
Nope. The T’s diesel buses have power only at the third axle.
See https://en.m.wikipedia.org/wiki/Articulated_bus#Pusher . This is the modern design.
Pullers, with the middle axle powered, have the engine under the floor in the front section.
Front end has a plan, but back end don't care. I remember rear wheel drive back in the day, I drove a heavy V8 boat with balding tires and a bunch of sand bags in the trunk. Good times.
My first car was a Ford Ranger. A little rain with no weight in the back and the wheels would lift up when you pushed the gas from a stop.
There would be no problem!
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