HST's in the south east region?

Well, the old Eurostar connection IC125 services from Manchester used to run into Waterloo. I believe only short wheel based Mark III coaches could travel over third rail track although this rule was convieniently forgotten at Watford Junction.

Short swing link bogies. The swing link is part of the suspension that determines how the body moves relative to the bogie. The wheelbase and carriage length is the same on both types, AFAIK. I'm not sure which part of the carriage they're worried about hitting the third rail.

were HSTs used for the Brighton and Portsmouth XC services?

I am sure a positive 'no'. I would imagine that they were Class 47-hauled. However, Hastings units were used on the Brighton-west country services via Salisbury and I am not sure if any reversed at Portsmouth & Southsea. I can only recall WR DMUs and SR DEMUs on the Portsmouth-Bristol/Cardiff services.

remember that! was travelling back from boring devon at the time, but the problem was the next first great western service to london waterloo from torquay was about an hour so we had to take a 159 stopping service! grrr damn first worst great western

I remember when I was a student there used to be boat trains that ran from Liverpool to Dover Western docks via London Olympia, I used to catch these a lot and change at Bromley South, I can ´t for the life of me remember how they were hauled, I think it started with an HST, but we used to stop for some time in Olympia so they might have swapped for something else. Definitely Mark III coaches all the way though.

The more I read this thread, the more I'm convinced I've seen a pic of an HST at Brighton! It was some years ago and may have been in '92 when they first started working to the south coast on the Bournemouth and Poole work. I think the pic was in the 'Railway Magazine'. Thats the worst of old age. Firstly,the memory starts to go and secondly, err umm.... What was I talking about?

As mentioned in previous comments, only Mk 3 carriages with "long swing link" suspension are banned, as the body can move further relative to the bogies. 442s are presumably fitted with short swing link suspension.

The HSTs used on the Cross-Country services had SSL bogies. On Gensheet (a reputable forum so can be mentioned) reference was made to The Royal Train (in connection with a query as to whether HSTs had ever worked Reading-Redhill). It is assumed that the Mk3 coaches have SSLs, but it seems that specific reference is made to its permitted routings and speed limits. Perhaps swl can confirm please?

The short swing link bogie modification was indeed the precurser to Southern region ops. The swing link took the form of what looked like a loop of steel cable as opposed to the solid metal object that used to be there. The 'Plastic Pigs' (442s) had entirely different bogies.

No. The bogies themselves were new. It was just the electrical equipment that was salvaged from the late, lamented, 4-REP units. If ever there was a contender for the finest EMU ever built it was a REP. I timed one at well over 115mph one sunday at Wallers Ash. I was the Guard on the working and we ran from Basingstoke to Winchester in 13 minutes flat! That's an AVERAGE speed of 87.5mph... I also worked as Guard on one that managed Waterloo to Winchester inside 45 minutes. The Driver was not amused when I wouldn't ring the bells until 'right time'. 12 minutes we sat there! By the time I passed for driving EMUs they were long gone. Regrets, I've had a few.....

I like the photos of the Merchant Navies in the last years being thrashed at over 100 mph.

I can only recall ever seeing a 4-REP + 8-TC doing 100 once, when I peeked at the speedo in a TC cab. Makes you wonder what the trial 3 x 4-REP combo could have achieved with 9,900 hp! That would have been 1968ish?

I am sure that a 3 x REP combo has been done more than once but can anyone confirm please?

I seem to recall that there were suggestions of 115 or so with one or two MNs?

Apart from the REPs, what about the 'Clactons', supposedly the first 100 mph EMUs?