It will be a VLEY being on a PN Superfreighter, probably a/c Sadleirs.
VLEY is simply a VLEX with CCSBs (constant contact side bearers) in lieu of gap side bearers.
Thx for the teply
Constant contact side bearers?
The standard freight bogie these days is a 'three piece bogie' consisting of two side frames and a bolster east-west between them. (1+1+1 = 3
). Mid way across the bolster is a circular flat bottomed 12/14 inch diameter centre plate bowl 'queen casting' which is engaged by the 'king casting' on the wagon bolster. There is a vertical 'king pin' in the centre between the king and queen castings.
So far so good (I hope).
Somewhere on the bogie bolster, roughly half way between the centre bowl perimeter and the side frame, there is a device which matches a block on the wagon bolster. These are basically to control wagon body tilt side to side as otherwise everything depends on balance in the centre plate area. These may be either a gap side bearer of something around 10 mm (I forget the actual figure) which are simply two 'dumb' protuberances or there may be CCSBs where the bogie sidebearer is spring loaded to remain in constant contact with the body sidebearer. CCSBs improve wagon dynamics and thereby allow higher speed operation. Gap sidebearers must retain a specified gap at all times and CCSBs must operate at set loadings which are adjusted by shims under (on top of actually) the body sidebearer.
Hopefully I have remembered all this correctly. If not someone will shoot me down, no doubt.
EDIT 1743 on 12/6: The following will explain everything very clearly (unlike many other rail documents these days). Full credit to the document authors in this regard:http://www.asa.transport.nsw.gov.au/sites/default/files/asa/railcorp-legacy/disciplines/rollingstock/esr-0545.pdf