My Airport Operations

Thanks Ben-

Would you happen to have any documentation from Ford?  My mechanic is hesitant to do it unless I can show him that this has been hashed out elsewehre already.

Thanks.

Keith

Keith,

Sorry I didn't get back to you sooner, I got my answer the next day and it slipped my mind.

We did not have to do any modifications to our ABS systems to properly use the Bowmunk. I'm being told by my Assistant Chief that our management asked these same questions years ago, before I started here, and that Bowmunk made specific calibration updates to make sure the units would not be affected by ABS kicking in.  There was a concern of liability and safety for our AOS's driving vehicles where the ABS was not operating at all times.  And like I said earlier our "mutt" of a vehicle fleet includes 2 2008 Jeep Grand Cheerokees, 6 Ford Escapes (multiple model years) and one older model Ford Explorer.

If you need any more specific specs I'm sure I can find out soon when our Bowmunk rep comes in for annual training and maintenance this month.

Good luck with your snow seasons, all!

Keith, 

one more thing..We have this installed 2005 GMC Yukon (newer vehicle)

Keith,

Brian Thompson, Rochester Int'l Airport (RST), Minnesota here... We use the Vericom VC3000 decelerometer.  I had our maintenance department install toggle switches that will disable the ABS while we are in snow removal operations, but also have the ability to activate ABS while driving land side. I am not an auto mechanic but I believe the toggle switch was wired somewhere in the fuse panel.  I can get more info on how to do this if you like...Works well for us...

@Ops GuyZ We're using the mechanical bowmonk.  I've found the Tapleys to be maintenance hogs in my experience, so we don't use them.

I'll get back to you about our situation at ORD.  We have two Dynatest Ford F-350's as well as a hand full of bowmunk units.  We have the AFM2 units...I assume that's what you are using?

As far as I know we do not have the ABS modified at all on our vehicles (2 Jeep Grand Cherokees, 1 Ford Explorer, 6 Ford Escapes), but this I will check for you.  I do know that the vehicle does not actually need to come to a stop when running the test so the ABS wouldn't necessarily kick in for every test completed.  

I'll also check with my old co-workers about using the Tapley meters that were installed directly into the vehicles and see if they have their ABS modified (I don't recall it being done).

Anyone else?  It appears that disabling the ABS is imperative, but how to to it on the newer vehicles is the question.   

The AC states the decelerometer:

Be equipped with either standard disc and/or drum brakes as long as they are maintained according to the manufacturer’s performance requirements.  They can also qualify if they have a single sensor ABS (anti-lock braking system) installed on the rear axle.  Decelerometers should not be installed on vehicles that are equipped with full ABS because the ABS tends to distort the sensitivity of the decelerometer resulting in friction readings that are lower than actually exist.  In addition, differences in ABS systems result in high variations in friction readings.  This could result in the premature closing of runways.  A full ABS has three sensors, one on each front wheel and one on the rear axle.  Decelerometers can be installed on these vehicles only if the manufacturer of the ABS approves disengagement of the sensors on the front wheels.  If this modification can be satisfactorily achieved, the vehicle’s brake system then becomes a single sensor ABS installed on the rear axle, which will then qualify the vehicle for conducting friction tests with decelerometers.

We have a BOWMONK and have always had a toggle switch as well to disable when we conduct friction tests. We are getting ready to equip a 2009 vehicle and we are checking into the portion of the AC in which the rear axle is left with ABS capability. I will try and get you more as we work through this as well.