I was just cruising through the site, and found your comments.
You're quite right about the hard pan underneath, a matter that concerns me all the time. I'm sure some of my owners wonder what I am on about when they see other horses race and apparently suffer no ill-effects....mine, at the moment, all require a bit of 'cut' and we are just sitting out the dry weather.
The bark chip had the potential to be good....but the installation was sloppy and poorly done. The ground upon which the bark was to be laid was not prepared in any way, and the material was just dumped on top of an undulating surface. Result being, that some portions were deep - and broke down at a different rate to the more shallow areas.
We did a heap of work on it and never had a problem, but were always careful to not let the horses off the bridle.
The reconstruction done in 1998 was carried out by Laing's....not sure whether you are right about them 'flogging off' the topsoil....seems likely someone did, but can't point the finger at them.
I rang Duncan Laing some time after, when there was a bit of controversy about the track. He was very approachable, athough by then he had sold his company and was doing consultancy work.
He told me that the track was re-laid according to the scope of work given to them by the [ then ] RIB. After talking to him, I reckoned that the depth of topsoil laid according to the plan wouldn't have grown decent carrots!
It has not been completely satisfactory, but I think it is a little unfair to blame the company. It is not their job to question the scope given to them.
The underlying clay/scoria layers - cambered - were supposed [ as I understand ] to create a means to channel water from the subsurface and to the drains on the inner. They don't work as they were intended, and subsequent work on the track with vertidrainers, etc, has brought the clay up where it becomes like Yaldhurst road when dry, and a bog when wet.
There has been sanding/coring done, but, although my knowledge of such matters is sketchy at best, it seems to me that sanding should be done way more often.
Up the road at Rangiora, sanding/coring is done very regularly and the surface, once the subject of criticism [ flawed reconstruction also ] is now very good indeed - even when firm.