"Tony Polson" wrote in message
...
wrote:
In article ,
(Tony Polson) wrote:

Perhaps some more recent Tube stock could be purchased instead? The
Victoria Line stock is being replaced. I know its alloy construction
would be less than ideal but perhaps some high tech corrosion protection
could be applied? Using old rolling stock on the Island is in keeping
with the long established tradition of using secondhand stock from the
mainland.

Isn't the problem with older tube stock, including the 1967/72 TS, that it
isn't alloy enough? In other words the combination of aluminium bodies on
steel underframes is the real corrosion headache on Ryde Pier?


Quite possibly.

How much of an issue is corrosion on the Island Line? Are they really on the
pier for long enough periods of time that it can become problematic?

wrote:

How much of an issue is corrosion on the Island Line? Are they really on the
pier for long enough periods of time that it can become problematic?


Good questions!

I'm no expert on corrosion, but I do know that dissimilar metals in a
marine environment can cause no end of problems. Once exposed to salt
spray, an electrolytic reaction starts between the metals using salt
water as the electrolyte. There is very little you can do to stop it.

So the issue is not how long they spend on the pier. I think the issue
is that they get sprayed with salt water and that sets up a corrosion
mechanism that continues while they are away from the pier, and into the
long term.

In article ,
() wrote:

How much of an issue is corrosion on the Island Line? Are they
really on the pier for long enough periods of time that it can
become problematic?

I remember being told many years ago that their aluminium bodies on steel
underframes was why no 1959/62 stock ever went to the island.

--
Colin Rosenstiel