Technical Memorandum "Rs

To: Ethan Melone, SDOT
From: Tom McKerlick, RE.
CC: Mark Dom, RE.
Date: July 25, 201 1

Subject: Streetcar Rail langeway Treatments

 

The purpose of this memorandum is to discuss standard practices for installation of in?street
embedded streetcar trackway, and potential modi?cations for minimizing rail ?angeway width.

Streetcars systems are designed to operate in existing roadways and other public areas, sharing space
with general traf?c, cyclists and pedestrians. he trackway needs to accommodate a groove, or
?angeway, to allow roadway paving up against the rail while maintaining an opening for streetcar
wheel ?ange passage. The preferred rail design for this application in the United States is known as
Ri-52 girder rail. This girder rail, has been installed on Seattle?s streetcar and light rail transit (LRT)
systems. It has a ?angeway width of about 1 5/8 inch which is the minimum required for wheel
?ange clearance in sharp curves, and was speci?cally designed to meet Americans with Disabilities
Act (ADA) Guidelines in the United States.

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TRACK (17.

w" SHALLOW TRACK Ri52 RAIL
SLAB CONCRETE 

 

 

WITH BOOT
:x (REFER 10-Girder Rail and Wheel Section Simpli?ed Streetcar Track Slab Section

It should be noted that ADA Guidelines allow a flangeway width of up to 2 V2 inches which is the
width commonly found in Tmrail applications such as light rail transit crossings.

It has been requested that the First Hill Streetcar design team explore options for a potential ??ange?
?ller? design application. There are no standards or products available for closing or narrowing girder
rail ?angeway. However, there are two types of products available for T?rail.

Flangeway minimizers are commonly used at freight or light rail crossings with high pedestrian traf?c
such as Amtrak stations. These products can narrow the ?angeway to as little as 1 V2 inches, which is
only narrower than a standard girder rail ?angeway.

Flangeway ?llers are commonly used in indoor industrial rail applications such as maintenance
facilities, where workers and equipment frequently cross tracks, but rail traf?c is minimal. They
completely cover the ?angeways for ease of crossing the trackway, but the weight of a rail vehicle
compresses the filler material to allow its wheels ?anges to pass. Flangeway ?llers are recommended
for indoor use only as they must be kept relatively clean and dry. Buildup of debris and/or icy

 

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Asphalt

 

conditions can increase the stiffness of ?angeway ?llers to a point where they will not compress under
a rail vehicle?s weight, and can cause derailment. They are occasionally used where low-traf?c, low-
speed freight rail sidings cross roadways at skewed angles. In such applications a derailment would
be unlikely to cause injury.

Rubber fIlIPf? between Rubber znsert Rubher Insert
rud 8. nsphult - "lo form ftungewuy - Inflated to fill gap

Rubber filler be ween deflated to allow for wheel flange
asphalt

   

   

--Asphull

 

 

Sleeper

Sleepe

 

T-Rail Flangeway Treatments

A drawback of T-rail speci?c ?angeway products is that to adapt them to streetcar use would require
compromise joints at all girder rail interfaces, and the rail and joints would require unique embedment
designs and electrical isolation systems.

A speci?c case of outdoor use of ?angeway ?ller was brought to light during research for this memo;
the Cherry Avenue Bridge in Chicago is a historic railway bridge that was refurbished and converted
to a pedestrian and bike-only facility in 2009. Rubber grade crossing panels and ?angeway ?llers
were installed between the existing T?rails to cover the bridge deck while allowing for infrequent, low
speed passage of freight engines.

A 
?un?t 
II

 

Cherry Avenue Bridge, Chicago Bridge Deck Detail

 

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While the project has been successful in its goal of creating a good surface for pedestrians and cyclists,
its environment is not comparable to that of an active streetcar line.

The Cherry Avenue Bridge is used by only a few trains each year, and only in well controlled
conditions. The light, non?motorized traf?c on the bridge keeps the deck relatively clean without
frequent maintenance.

A manufacturer?s representative who supervised the installation of the materials on the bridge said he
would not recommend their ?angeway ?ller for in-street use because it was not designed for frequent,
higher-speed rail vehicle traf?c, or for dirty or freezing conditions. He also said he was aware of no
other products designed for this purpose.

In conclusion, there are currently no products available or methods commonly in use that are capable
of improving on the standard girder rail design and ?angeway width for in?street use on streetcar
systems.

 

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