Friday, December 22, 2017

Response to questions about curves on rail lines

With the recent derailment of an Amtrak Cascades train, we wanted to talk a bit about the Point Defiance Bypass and our agency’s work to develop it for Amtrak Cascades passenger train service. Our thoughts remain with the passengers and families involved in the tragic Monday, Dec. 18, derailment and we want to answer questions that have arisen about the tracks where the train derailed.

Long-range planning to develop these tracks for expanded passenger rail service began more than a decade ago and was initially conceptual – looking at all possible options. The long-range plan referenced in recent media stories states it was developed “without financial constraints” and goes on to explain “as a result, the plan’s ‘building blocks’ with the operational benefits are intended to be implemented incrementally.”

As a transportation agency, we must always balance providing service goals with funding and schedule constraints. Our goal with our recent improvement project was to provide better reliability and six Seattle to Portland roundtrips. The work done on the Point Defiance Bypass – and the rest of the tracks from Blaine to Vancouver, Washington – achieved those goals, allowing us to continue to travel at the same maximum speed as before – 79 mph – but improving the reliability of our service and giving travelers two additional options for daily roundtrip service.

The track configuration as it exists today meets all Federal Railroad Administration requirements.

The bypass tracks have a reduced speed limit before the curve where the derailment took place to inform engineers to decrease their speed to negotiate the curve. The maximum speed limit decreases from 79 mph to 30, with signs posted two miles before the speed zone and just before the speed zone approaching the curve. Amtrak is responsible for ensuring all engineers on this specific set of tracks are qualified. It is common for railroads to have areas of reduced speeds due to curves or other factors, as found along the entire Cascades route.

Trains successfully ran the bypass track numerous times in the past few months during track testing, locomotive testing and engineer qualification on the tracks, and the ceremonial train ride with passengers on Dec. 15 during the new station dedication.

The investigation by the National Transportation Safety Board (NTSB) will determine the cause of the derailment and we cannot speculate as to what caused it while the NTSB conducts its important work. We’ll continue to share updates and any information we can while the NTSB investigation continues.


funnelfan said...

But much like a 70mph highway going into a 30mph curve, there is always a highly elevated risk that the driver will not heed any warning and begin braking far too late to make the curve.

jWilliam Dunn said...

In that two mile slow-down approach to the curve, it seems that some radar speed signs would help. Those types of interactive signs can also be outfitted to trigger flashing lights, blasting sirens, radio broadcasts to central control, and ultimately, messages into positive train control systems.

WSDOT said...

jWilliam Dunn, thank you for the suggestion. The tracks met federal standards as-is and engineers were required to be trained on the specific route, but we will certainly pass that suggestion along to Sound Transit, the owner of the tracks. We also will be looking to the National Transportation Safety Board report for any suggestions or findings. For now, our Amtrak Cascades trains will not run on the bypass tracks until PTC is installed.

Toby Tyler Hilden said...

I've always been curious why track speed limit signs are as small as they are. It seems something close in size to automobile speed limit signage would be a visual benefit.

Joe said...

Great comments above, echoing my own thoughts: 80 to 30 is too drastic of a change to only have 1 sign. The second sign just before the bend doesn't count as it gives no time or distance to make any changes. If the speed reduced from 80 to 60 to 40, etc. the engineer would have an opportunity to slow down if he missed the initial sign. We don't have 65mph highway speeds leading up to 25mph school zones for a reason.

People can say PTC would solve the problem all they want, but a good design wouldn't rely on one single little sign to signal such a drastic speed reduction. At 80mph it seems easy to miss the sign, regardless of whatever training. I understand the tracks met standards, so I believe the standards need to be changed. I also believe that it's our duty as civilians, engineers, planners, etc. to do the right thing, whether or not that goes above and beyond federal mandates.

dave said...

A few points and questions.
1) Interesting that the "Amtrak Cascades trains will not run on the bypass tracks until PTC is installed". To me that would imply that the other route has PTC. Is that correct? If PTC is not on the other/old route, then why is it being preferred until PTC is installed on the bypass tracks? Are you going to stop other routes until PTC is installed? If not why this one and not others?
2) There seems to be no question of how fast the train was going at the time that it derailed. Only a precise, full analysis of things like why it was going that fast, did the breaks not work, did train personal follow procedures and escalation procedures, should it still have made the corner even at 80 MPH (posted speeds a fraction of the max speed calculated and engineered).
I'm curious what the calculated speeds are for the corner for jumping the track, the train tipping off the track, and the track itself failing (breaking, sliding, sinking). That had to (or should have) been engineered in the the design of the track and the calculated selection of the 30 MPH speed limit.
3) It is very understandable that there is not an unlimited budget available and many things factor into the building schedule including federal requirement dates, projected available funds, the costs of implementation, and the calculated risk of running with and without all planned safety features (PTC). Insurance cost will likely be affected by adoption of PTC.
4) I really like some of the suggestions by others here for things that may not be as good as PTC on it's own but would cost much less, could be implemented quickly and still be a benefit after PTC is completed and that they will be passed along to Sound Transit. I hope they will be also passed along to Amtrak and other track owners.
5) How about a smart phone app that incorporates some of the PTC alert features. It can use GPS and accelerometer to know where it is and how fast it is going, map data to know how fast it should be going and areas that personnel should be especially attentive of. Car driving apps like Waze have those features already. Might just contract one of them to create the train app. With no physical changes to existing tracks or trains required it should cost much less and be much quicker to implement and utilize the same data that will be used for PTC.
6) Get apps like Waze to add a report feature like car/object/obstruction on track/road crossing. And maybe other track problem observations like crossing light out or arm not working. Take advantage of the internet of things (IoT).

WSDOT said...

dave, thank you for your comments.

I’d like to include a link to our recent FAQ posting:

Some of your questions are part of the on-going NTSB investigation and we can’t comment at this time, but I did want to add these:

1) The existing train route does not have PTC activated for passenger trains. Given its 20 years of successful boardings, however, trains will continue to use that route. The decision to not return to the bypass until PTC is activated is due to sensitivity, both those involved in the tragic derailment and future passengers.

4-6) We can pass along your suggestions.

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