The Eames Vacuum Brake.
The Eames Vacuum brake was a simple straight vacuum system where an ejector in the locomotive withdrew air from the train pipes and brake cylinders to apply the brakes, and was adopted by all the Maine Two Footers for their passengers trains. The system was cheap and simple; but it suffered from some disadvantages such as limited braking force available, speed of reaction down a long train and no automatic braking if the train parted.
In most railway applications, it was superceded by so called safety brakes. In North America, the Westinghouse Air brake became the preferred system, and actually made it onto one of the Maine Two Footers – the large Sandy River and Rangeley Lakes system. The other Maine Two Footers retained the simple Eames vacuum brake to their end, as it met their needs and its limitations did not cause sufficient problems to be worth paying for. Note that in 1890 the Eames Company reorganized as the New York Air Brake Company.
The Eames vacuum brake system is shown in these references;
Articles in the modelling press about this brake system include;-
Article by Bill Jensen – Gazette July 1977
Article by Moe Mechling – Maine Two Foot Modeler Aug 1989, Vol 21
Components for modelling the Eames vacuum brakes on the Maine Two Footers are available from Coronado Scale Models and Precision Scale Models. These include the Bridgton style vacuum brake cylinder used on freight cars (Coronado part BC-142);-
and the alternate diaphragm cylinder used on the SR&RL (Coronado part BC-141);-
Modellers should note that vacuum rubber hoses have a much larger outside diameter than similar capacity compressed air hoses, and should refer to prototype photo’s published in books for further details.
For up to date information about safety vacuum brakes and their railway application visit;- http://www.railway-technical.com/vacuum.shtml
An up to date description of the air brake system as applied to railways is available from;- http://www.railway-technical.com/air-brakes.shtml and there is an interesting article about North American Freight Train Brakes at ;- http://www.railway-technical.com/brake2.shtml
Components for modelling the air brakes found on the SR&RL are available from Precision Scale Models, Grandt Line and Foothill Model Works.
Typical 1900’s Air Brake system
Diagram of Westinghouse Quick Action Automatic Air Brake equipment circa 1901, originally supplied by M Derkerg, 7/8ths Group, Yipespipes files.
Air Brake installations typically used on the SR&RL
Diagram of Westinghouse Type “K” Automatic Freight Brake equipment as applied to freight cars circa 1920, originally supplied by M Derkerg, 7/8ths Group, Yipespipes files.
The SR&RL used the lower (KD) installation on its freight cars, for further details see Gary Kohler’s book on the SR&RL Freight cars. This book includes model sized plans showing the brake installation and a picture of a de-railed car on its side showing all the prototype details.
Trevor Marshall has kindly provided the above two pictures showing one of his boxcars models, based on a SR&RL prototype, showing how he modelled the revised (air) brake gear.
SR&RL Locomotive #10
Diagram of Westinghouse Combined Automatic and Straight Air Brake equipment as applied to SR&RL No. 10, circa 1928, originally supplied by M Derkerg, 7/8ths Group, Yipespipes files.
SR&RL Locomotives #23 & #24
Diagram of Westinghouse #6-ET (Engine, Tender) Air Brake equipment as applied to SR&RL No’s 23 and 24, circa 1923, originally supplied by M Derkerg, 7/8ths Group, Yipespipes files.