Hi Spaw,Thanks for the compliments about our Kiwi yachties - guess they started in P-Class or Sharpies..;^)
Our railway(road) engineers were pretty sharp 120 years ago, adapting your Yank technology to 3'6" gauge...;)
Now, since we're way off "demijohn" topic and "tamping frogs" here's a red "herring" (no that's another current thread) - OK railway buffs - "Frog" - Wasn't that also the open-mouth thingie, that Europeans bolted to "sleepers" (ties to you), to tie down their bull-head rails?
Maybe "tamping frogs" was driving in the two wedges to tie the rail to the frog that tied it to each and every tie ("Sleeper" to me) - hey - weren't us Colonials more practical with our flat base rails, that you spiked direct to the sleepers...;^)
Spaw, I'm sam@southnet.co.nz get in touch.
When I've time, and worked out the Mudcat posting complexities, I'll throw the words for a few Kiwi railway songs your way.
Cheers - Sam