Turning Tag Axle

[afrench45]

Im just curious, does anybody know what was the first coach to have a turning tag? I know it was sometime in 2004, but don't know around what coach number.

[fulltiming]

I know that coach 701 has a steerable tag. That is lowest numbered Newell I have seen with a steerable tag but there could have been a few built before that. I show that coach 694 did not have a steerable tag.

Remember that it is not uncommon for Newell to build a single coach with a specific feature then build a number of coaches without the feature to allow time for them to test it before making it standard.

[RussWhite]

Michael,

I ended up parked next to a Newell with the steerable tag here in Tucson. I got to wondering what makes it turn and how that works. I couldn't easily find an explanation and hoped you might point me in the right direction or give us a quick explanation.
Thanks,
Russ

[fulltiming]

Russ, ZF makes both an active and a passive steerable tag axle. Newell uses the active steerable tag. While both of these tag axles function much like a non-independent front suspension, the passive tag uses steering dampers and pneumatically actuated lock cylinders to allow the tag wheels to turn together but limit the amount of turn. The active steerable tag uses a hydraulic cylinder to control the steering. The cylinder keeps the tag parallel with the drive axle most of the time. When the front wheels turn past 5 degrees, the hydraulic cylinder begins to turn the tag axle in the opposite direction. As the front wheels continue to turn sharper, the tag axle increases up to a maximum of 23 degrees. According to Newell, the turning radius of a 45' Newell is reduced from 44' without a steerable tag to 37' with the steerable tag.
2284
See http://www.zf.com/media/media/en/document/corporate_2/downloads_1/flyer_and_brochures/bus_driveline_technology_flyer/Bus_Antriebstechnik_Achssysteme_ZF.pdf for drawings (including the one above).