Rail

BART replacing old third rail for a smoother and more reliable ride

Posted on August 7, 2019 by By Melissa Jordan, BART Senior Web Producer

New, stainless steel-capped aluminum third rail segments stacked in a warehouse.
BART
New, stainless steel-capped aluminum third rail segments stacked in a warehouse.BART
A key part of BART’s Measure RR rebuilding work is renewing power infrastructure, a major upgrade that will improve the rider experience through greater reliability and less down time for repairs.

Along with cable and traction power substation replacement, part of the job is replacing sections of third rail, the electrified rail that powers BART trains.

Stacked high in a chock-full storage warehouse are stainless steel-capped, aluminum third rail segments that will be more efficient and economical. The new rail is half the weight of the old and conducts electricity better.

That means easier and faster installation, because the old rail weighed in at 27 pounds per foot or 810 pounds for a typical 30-foot segment or “stick,” more than twice the weight of the new rail. It takes many workers to handle such a heavy load, and the old rail is also six times stiffer than the new, making it tough to position just right. With the new rail, BART can do repairs more quickly, requiring less down time and inconvenience.
Close-up detail of the new third rail that is stacked in a warehouse waiting to be used.
BART
Close-up detail of the new third rail that is stacked in a warehouse waiting to be used.BART

The warehouse holds some 2,400 sticks of new rail, at 12 pounds per foot, or 360 pounds per stick. That’s light enough to require far fewer workers to handle. There’s a thick aluminum bar to conduct electricity, covered by a tough stainless steel cap for resistance to the countless iron paddles from train cars that slide across its top, transferring power to the train.

“Third rail is an important asset for reliability of the power system and continuous train operation,” said Myat San, BART’s Group Manager for Power and Mechanical Engineering. “The useful life of these third rail segments is about 20 years. As they age, efficiency and performance will be impacted.”

Back in the 1960s and 1970s, Kaiser Aluminum (no longer in business) supplied all of BART’s third rail for the core system.

Old Kaiser Aluminum rail, past its useful life, is put into a scrap pile for removal.
BART
Old Kaiser Aluminum rail, past its useful life, is put into a scrap pile for removal.BART
There were two styles, a regular one at 4 micro-ohms per foot (an ohm is a standard measure of electrical resistance) and a more conductive version known colloquially as “double-stuff Oreo” at 2 micro-ohms per foot. The more conductive one was considerably more expensive and used in areas with long distances between traction power substations.

The original third rail was made by standing 30-foot steel I-beams vertically in molds, and pouring in molten aluminum for a strong bond. It was symmetrical top and bottom, so when the tops wore out after about 20 years of use, BART electricians simply flipped them to use the other side. Eventually both sides would wear out and require third rail replacement.

By around 1990, with much of the third rail in high-wear areas at the end of its useful life and with no more Kaiser Aluminum to provide new rail, another manufacturer provided for core system replacements, as well as for new extensions to the BART system such as to San Francisco International Airport. This rail is the heavier, less conductive rail in much of the system today.

A corroded, weather-exposed rail cross-section, left, and a pristine sample.
BART
A corroded, weather-exposed rail cross-section, left, and a pristine sample.BART
BART also decided to make all new third rail the thicker aluminum 2 micro-ohm/ft. version—the double-stuff Oreo kind -- to reduce voltage drops and improve train performance between substations. Third rail voltage has direct impact on train performance, and thus it is important to maintain it at acceptable levels.

Several years ago BART tested a new, stainless-capped aluminum third rail product that offered many advantages, and test sections were installed south of Bay Fair Station to see how it performed. After successful tests, BART is moving forward to install it systemwide, replacing legacy 4 micro-ohm rail with the more economical, more conductive, lighter and more flexible new rail. That’s good news for passengers, who can expect a smoother, more reliable ride from the new third rail, the backbone of power for the whole BART system.

“The Measure RR work we are doing to replace substations, transformers, third rail and more, is about reliability and a better experience for BART’s riders,” San said.

BART District voters in 2016 approved the Measure RR infrastructure bond for rebuilding the system. For more information, visit our Measure RR rebuilding website.

View comments or post a comment on this story. (0 Comments)

More News

MBTA double-track project gets go-ahead to proceed to next phase

The work will improve reliability and support future network growth by adding double-track segments to the Franklin Line.

MARTA purchasing 254 Stadler railcars

The procurement is the single largest for either organization and aimed at more efficient performance and enhanced customer experience for MARTA and its customers.

Amtrak cites customer satisfaction, safety as factors for record ridership

This year, the agency became the first major U.S.-based railroad to implement a Safety Management System, a proactive approach to managing safety, resulting in significant improvement.

Joint venture celebrates Stage 1 of Ottawa's Confederation Line

A team including STV and AECOM played a critical part in the design and construction of the line.

LIRR begins PTC usage on 4 more rail lines

The segment of the Montauk Branch between Babylon and Patchogue received the technology in April, and the Hempstead Branch received it in August.

See More News

Post a Comment

Post Comment

Comments (0)

More From The World's Largest Fleet Publisher

Automotive Fleet

The Car and truck fleet and leasing management magazine

Business Fleet

managing 10-50 company vehicles

Fleet Financials

Executive vehicle management

Government Fleet

managing public sector vehicles & equipment

TruckingInfo.com

THE COMMERCIAL TRUCK INDUSTRY’S MOST IN-DEPTH INFORMATION SOURCE

Work Truck Magazine

The number 1 resource for vocational truck fleets

Schoolbus Fleet

Serving school transportation professionals in the U.S. and Canada

LCT Magazine

Global Resource For Limousine and Bus Transportation