So Miami Airport Station was designed too short and now Miami Central was designed too narrow!

(This post is in the wrong category on the forum.)

Looks like Brightline's fault for building it this way. BL says it read the high-speed specs instead of general specs that would apply to Tri-rail. There are two issues though:

1. Platforms too wide - nothing to do with high-speed specs, right?

2. Elevated rail too steep - it's about weight, but maybe power/weight ratio. I don't know that high speed trains necessarily can climb hills better, but apparently there's a spec. Tri-rail trains are a lot taller, could tip?? The article says they want to know if they can climb the hill "safely." Also, the article says "90% less than" when it probably means "90% of" the Tri-rail requirement.

There's sniping between board and management and politicians, about it just coming out now when the report was written in March (shades of DC. Metro on the wheels slipping across the axles, which was known for years), as well as Tri-rail blaming Brightline, which isn't refuted. No comment from Brightline.

It's hard to believe Tri-rail didn't review the engineering, but you could say the same thing about Amtrak at the airport. Maybe they didn't want to, for legal reasons. Or we've got some major league shenanigans going on.

It's a Miami Herald story by Douglas Hanks, for anyone who missed the tiny Herald logo, as I did.

The weight issue, as I understand it from the board meeting yesterday, is that the viaduct structure was supposed to be designed to AREMA standards, which is to support 200% of the anticipated maximum load. The viaduct was actually designed to support 120% of the anticipated maximum load. This is how it was explained by staff to the board.

I’m not sure how that squares with the report (which I haven’t read) and/or the Miami Herald article.

Jim

Here is report;.
https://www.miamiherald.com/latest-news ... ore_inline

Could it be that the steepness is because too quick to ramp will cause tops of Tri-Rail cars to strike each other?

Two Siemens SCB-40 locomotives powering as many as seven Siemens Venture passenger cars should have no trouble climbing a 4% grade. One Brookville BL36 or GP40 conversion would struggle with more than three Bombardier commuter coaches on the same grade. In order to keep the viaduct short I would expect a steep grade as long as your trains can handle it. As for weight I would expect the single level Siemens Venture coaches to weigh less than the Bombardier double level commuter coaches, then add in passengers, fifty in the Venture coaches, ~140 in the Bombardier coaches.

It is not the weight of the cars but the weight of the locos!

This is really bad. Just two examples from the summary:

“Augercast piles shall not be used on the project.”
(See page 100 of the Report.) Per the plans provided by Brightline, the original five 42-inch-diameter
drilled shafts were replaced with seven 24-inch-diameter augercast piles. This appears to be a
construction shortcut that resulted in a huge cost savings for the contractor.

Secondly, due to the
concerns with construction quality, it is recommended that a sonar scan of the concrete be performed
to determine the actual rebar placement, size, and depth, and to check for foreign objects and voids
throughout the passenger platforms, concrete deck, and the plinths within the direct-fixation segment
of Tracks 4 and 5

let us see 42 inch diameter 21 radius = 21 x 21 x5 = 2205 . Now 24 inch 12 radius 12 x 12x 7 =1008.
That is less than half the the spec.

"Modify your cars and locos" (Brightline)

https://www.trains.com/trn/news-reviews ... t-station/

MIAMI — Tri-Rail and Brightline are each suggesting the other party is at fault after Tri-Rail management told the agency’s board last week that the commuter agency’s trains would not clear the platform at Brightline’s MiamiCentral station [see “Tri-Rail service to Brightline’s Miami station faces clearance issues …,” Trains News Wire, Dec. 13, 2021].

The website Florida Politics reports Tri-Rail Executive Director Steve Abrams told the Miami Herald his agency “did have an oversight role” in platform construction at MiamiCentral, “but we’re not pouring the concrete.” But in a letter to Abrams released Wednesday, Brightline President Patrick Goddard said his company believes “the most significant impediments” to Tri-Rail service “are issues related to the rolling stock, not the physical plant of the station.” It notes that both sides have been aware of the problem since April and that changes to the cars would be the easier solution.

“We understand and acknowledge that, as constructed, there are clearance envelope intrusions that we must resolve,” the letter reads. It further says Brightline believes, “and you and your engineering team concurred, that the most logical, expeditious, and non-destructive solution to remedy this conflict would be … slight modifications to the step structure in order to accommodate the variance within the Station.

"slight modifications to the step structure"

Ah, so that's the problem. The stairs on the Tri-Rail cars must be colliding with something.

Is this like the problem LIRR had with gaps that were too big, replaced by 'extenders' on the car floors in doorways that were in turn too big for the gap so hit the platforms?

andrewjw wrote: ↑Sat Dec 18, 2021 4:51 pm "slight modifications to the step structure"

Ah, so that's the problem. The stairs on the Tri-Rail cars must be colliding with something.

It is the door sills, not the stairs. TriRail uses low floor cars with doors having protruding sills.

That extra couple inches on the Bombardier cars could matter. They stick out as far as a grab rail. Not sure if that's standard or an option.

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electricron wrote: ↑Sat Dec 18, 2021 10:27 pm It is the door sills, not the stairs. TriRail uses low floor cars with doors having protruding sills.

Actually, it is the step. There is a small step just below the level of the door sill, and according to the consultant report drawings, it is that step that fouls the platform.

Jim

https://en.wikipedia.org/wiki/Bombardie ... _Coach.jpg

Do you mean the protrusion sticking out at the door sill?
Is it another step if it is not 6-9 inches below the door sill?