AAA Sales & Engineering: Skate Retarders

Model F4 Skate Retarder	download sales sheet \| view parts

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The F4 skate retarder is designed to stop cars and
hold them in position. The F4 is weight responsive, providing more braking force to heavy cars and less
force to lighter cars.

Retarder Rating (MPH)
Retarder Length	No. of Lever Units	Maximum Entering Speed
Retarder Length	No. of Lever Units	33 Wheels	36 Wheels	38 Wheels
4' 7"	2	3.0	3.0	2.9
9' – 2"	3	4.3	4.2	4.1
13' – 9"	4	5.2	5.12	5.0
18' – 4"	5	6.1	5.9	5.8
22' – 11"	6	6.8	6.6	6.5
27' – 6"	7	7.4	7.2	7.1
32' – 1"	8	8.0	7.8	7.7

Field studies verify that the 8 lever F4 retarder applies nearly twice as much braking force as an AR2 retarder
and 2/3 more braking force than our competitor.

Field Test Performance
Retarder	Squeezing Force (lbs)	Friction Coefficient	Friction Force (lbs)	Advertised Energy Removal
AR2	29.333	0.42	12,319	350,000 ft lbs
Competitor	34,000	0.42	14,280	Not Known
F4 (Light Car)	9,457	0.42	3,971	1.99 feet
F4 (Heavy Car)	56,745	0.42	23,832	Velocity Head