The Saab Friction Tester – Six Years Ago Today

Posted on 10. Sep, 2007 by in 2000-2009, 900, New England, Saab Stories

On September 10th, 2001, a whole six years ago today, I spent the day as the President of the New England Saab Association, walking the tarmac at Burlington International Airport of Burlington, Vermont. My how times have changed.

Below is the original article I wrote including photographs above.

Saab Friction Tester – Burlington International Airport

On September 10th, 2001 while I was visiting Burlington, Vermont I decided to finally stop by at the Burlington International Airport to see this widely spoken of “Saab Friction Tester” (SFT). To my amazement, the stories stood true to form as I found out that the airport did have a 1986 Saab 900 Turbo which has been in good working order since it was brand new. Once I got got this message from the receptionist at the airport administrative office, I eventually got the opportunity to meet the Airport Facilities Manager who graciously showed me the SFT inside and out! The overall condition of this Saab, combined with my sheer amazement that I was actually able to examine it was just a dream come true! From popping the hood to opening the trunk, this was one experience I will never forget!

To start with in introduction to the Saab Friction Tester I should inform you that and I quote “it is a sophisticated measuring deviced designed to measure surface friction on airport runways. It may be used for both operational testing, as an aid to ongoing air traffic; and for friction maintenance purposes.”

When not being used for testing purposes, the Saab Friction Tester may be operated as a general purpose airport vehicle.

The Saab Friction Tester is composed of three basic elements — the rear axle assembly, the computer panel, and the watering system

Rear Axle Assembly : The Saab Friction Tester is equipped with a special measuring wheel mounted behind the rear axle. The measuring wheel is connected to the rear axle through a chain drive which is geared to maintain a constant 12% slip on the measuring wheel vs the speed of the vehicle.

The raising and lowering of the measuring wheel is controlled from the driver’s control panel and is operated hydraulically. When the wheel is lowered onto the pavement surface, the forces acting on the wheel are transferred to the chain drive, which passes over the torque sensor.

As the friction forces from the pavement vary, the tension on the chain varies, creating varying pressures on the torque sensor. The electrical currents passing through the strain guages within the torque sensor are affected by measuring these variations in the electrical current and converts the analog signals into “coefficient of friction” readings.

Computer Control Panel: The computer control panel is located on the console in the driver’s compartment. In addition to providing a variety of control switches, the panel also houses the electronic circuit boards which control the function of the friction measuring equipment; performs calculations and provides digital and printed output of the system.

Watering System: The watering system is made up of a 105 gallon water tank, water pump, nozzle and pressure gauge. The watering system provides a controled layer of water ahead of the measuring wheel for friction maintenance testing. (The watering system should not be used at temperatures near of below freezing)

In addition to the the SFT being used with with a Saab 900, it also currently being used on a Saab 9000, Saab 9-5 Sedan, Saab 9-5 wagon and trailer unit.

Once the grand tour was over, I got a chance to take a look at some of the literature from the Saab Friction Tester which included ample time to read through the official SFT workshop manual which is where a great deal of the aforementioned material came from.

The best part about the experience with the SFT was that while checking out the instrument panel, guages, computer control panel, I noticed that the Saab 900 had only 16,563 miles on it!

If I had the opportunity, I would love to purchase the vehicle since it is quite a rare Saab and it is in beautiful pristine shape throughout. One would only hope that when the 20 year contract with Saab runs out soon with the Burlington International Airport, they will decide to purchase another Saab Friction Tester because this one has lasted quite some time and isn’t showing any signs of going away anytime soon.

New England Saab Association

Contact Information
New England Saab Association
Post Office Box 119
Keene, New Hampshire 03431


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One Response to “The Saab Friction Tester – Six Years Ago Today”

  1. Dave Chase

    15. Dec, 2012

    The saab 900 friction tester was put up for sale on 12/15/12. Total miles 20000!!!!!!!

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