Green Line Type 10 thread

[BandA]

Remember the first Bluebird to go through the brand new Harvard Station towards Alewife? And the ?Ashmont ?Mattapan loop was too tight for even PCC cars? People are always screwing up the clearances one way or another.

[diburning]

I visited the mockup, and was honestly quite disappointed. There's significantly less interior room on the sections with trucks and seating (compared to Type 7/8/9) since the interior walls are significantly thicker (almost a foot thick). The aisles are narrow, and the seats are significantly shallower as a result. Compared to a CAF Urbos 3 (which these are reportedly derived from), there's simply far less interior room. Not sure what happened here.

The whole purpose of the public debut of the mockup was to solicit feedback from the public. Be sure to let them know how you feel about it!

[bostontrainguy]

Like they are going to change something because we suggest it?

[dieciduej]

The whole purpose of the public debut of the mockup was to solicit feedback from the public. Be sure to let them know how you feel about it!

Back in the day a mockup was built well before true metal was bent. This is end of 2024 with the pilot cars in the Spring of 2026.

As for the width of the walkway in the truck/bogie sections of the cars they will meet the minimum ADA standard of 32". That was my dislike, with people seating face-to-face in that section it is just about impossible to walkthrough unless sideways. The key on that point is the truck/bogie design, they are powered so a motor, probably some form of pancake design has to be wedged in, making the wheel thicker in a way. That is the constriction.

I really haven't traveled to Europe in ages so I don't know how their trams do it or is it just a fact of life in tram design.

[RandallW]

Like other modern designs, the CAF Urbos 3 is available in multiple widths.

From CAF's Urbos Trams Broouchure:

Suitable for all types of urban environments, the Urbos is offered in three standard widths: 2300mm, 2400mm and 2650mm. If required, it is also possible to provide a bespoke width.

Since the design also is available with axles fixed to the car, or on flexible bogies, it's entirely possible that the mockup is showing that, to navigate some part of the system, the MBTA needed a design with flexible bogies to allow them to avoid a narrower width (Wikipedia states the Type 10s are 2600mm wide) while being 100% low floor, and that results in obvious areas of perceived narrowness in the interior design to fit the bogies.

This image of CAF powered low floor bogies (I don't know if these are the "flexible" design or not) from the Luxembourg tram suggests that if the floor has be inside the bogie, it's going to feel narrower than if the floor were above the bogie:

[Disney Guy]

Don't forget that at articulation joints (six of them in a Type 10) the floor morphs as the car goes around a curve so that the available square footage of floor space where one can stand still is greatly reduced.

Swiveling bogies (trucks) further reduce the possible aisle width in a low floor car..

[MBTA3247]

Here's a photo of the interior of the 100% low-floor LRVs in Kansas City, taken from one end of the car. These are 3-section, 2-truck cars. Where the trucks are, you can see that it goes from 2x2 seating to 1x1, with the space where the missing seats would be taken up by the trucks. Worth noting that the seats by the trucks are transverse, not longitudinal, so the aisle isn't being narrowed by the presence of people's legs and feet.

7R314084

I think the T would be better off configuring the seats like they are in the Type 8 center section, with the seats above the trucks and a step between the seats and the aisle.

[dieciduej]

I agree with MBTA3247 that the KC low-floor LRVs with transverse seating would be a better fit.

[RandallW]

CAF offers the Turbos 3 trams in a configuration where the truck swivels with the section of the tram it is attached to and where the truck swivels independently of that section. Now for a question that I can't find an answer to: what style of trucks did Kansas City order and what style did Boston order?

From discussions about the SEPTA new streetcars, it appears there are known tradeoffs: the independently swiveling truck is quieter (less squeal), and allows an otherwise identical train to take tighter turns while the fixed truck is less expensive (less moving parts and less complexity), but can't take as tight a turn as the swiveling truck. I suspect another trade off is interior space.

[Disney Guy]

If a section has a single swiveling truck (bogie) then there must be a mechanism to prevent random nosing from side to side (random yaw). Traditionally this problem is prevented by the next section or articulation joint having one fixed truck or two swiveling trucks.

I suppose that someone might come up with a morphing underframe of linkages so the swivel angle of the truck under the section body is rigidly governed by the angle(s) the section makes with the previous and/or next possibly wheelless sections.

[HenryAlan]

Here's a photo of the interior of the 100% low-floor LRVs in Kansas City, taken from one end of the car. These are 3-section, 2-truck cars. Where the trucks are, you can see that it goes from 2x2 seating to 1x1, with the space where the missing seats would be taken up by the trucks. Worth noting that the seats by the trucks are transverse, not longitudinal, so the aisle isn't being narrowed by the presence of people's legs and feet.

I saw a report from somebody who met Phillip Eng when visiting the mock-up and said that he asked about this issue. The response was that they would need to use the configuration pictured in the KC Streetcar image to avoid the narrow aisles and it would mean giving up too many seats.

[bostontrainguy]

Hardly any seats now. Bring on the cattle cars.

[Disney Guy]

The Type 8 has a wider aisle through the center section because the wheels there are unmotorized leaving more spacefor seats and floor.