Nobody?

Not speaking from experience, but...

I guess I'll chime in, although I can't claim to be speaking from personal experience. Steel music wire seems to be the most common replacement, but there's no reason why phosphor-bronze won't work, as long as it is sufficiently rigid. Any fairly rigid and springy wire should work fine with your Tortoise. The longer the "throw" distance, the stiffer your wire needs to be.

--
Jostein

I concur.

  The spring steel would be a much better alternative to the PB. The PB will weaken over time until it bends or breaks.

       Pete

Speaking from experience

I have used .047 music wire for all of my Tortoise switch machines as I've found that the wire provided is just too thin to work effectively, especially with hand-laid turnouts. You can get the wire from K & S Precision Metals among others. You will need to drill out the hole in the switch machine using a #55 bit in order to accommodate the thicker wire. Here's a photo of several switch machines that have had the wire replaced.

Tom Patterson

Tom Patterson