19, started at about 6...
Been a volunteer at Puffing Billy for 13 years now (maybe longer actually), although until I was about 13 I only worked in the shop unofficially as such. After I turned 13, I became a conductor on the trains.
Now, I go to the 'young volunteer' days (got a few friends that join me, and it's fun to just to 'mindless' busywork, and I get to introduce the odd new non railfan to the railway for a day), and go to the museum at Menzies Creek to help with getting it re-opened
Seriously though. Part of the issue with younger generations not being into railways is the way that they are treated on the railways. It's good at the Menzies Creek museum in this sense, as we welcome anyone who's willing to work
Plus we also get to play with the stuff we restore
But many railways take their volunteers for granted, and this can start to bring them down. They end up treating volunteers poorly, and this causes volunteers to leave. And the younger people do tend to see these sorts of actions more clearly, and they simply stay away...
Of course, the other problem is that most don't have anything for those younger generations to strive for. They are all established, for the most part. Most aren't opening new sections of line, or restoring a new engine (as in the smaller unimportant engines that get shown off, not the big ones that only the 'trusted' people are allowed to work with), or even just restoring an original buildings. It's all done. Sure, there's a few extending their lines now, but it's normally a 'backburner' job, not something that a group can work on every weekend.
This then leaves the question. What is there to draw new volunteers in? What is there that can make the community want to help? Most railways will actually have at least one loco/vehicle that can be put aside purely for a younger group to become involved with to restore. This could be a small industrial loco, or even a historic wagon (e.g. a coal truck that may be associated with a loco being restored).
Granted, a restoration does cost money. But then, it will also bring in volunteers. But you do need it to be something interesting for younger volunteers to work on. Not a big engine that may never get done, and will likely never be driven by those younger members. But that small 0-4-0/0-6-0 tank loco that can be run around inside a museum compound, or in yard limits, by the restoration team (under supervision as needed of course), or at a minimum fired by the restoration team (again, under supervision as needed). Something they themselves can say "look at what I helped restored!", not something that the old guys can say "look at what we (the railway) restored!"
I'm not saying this is always the way it is. This is simply my own point of view on this issue, a point of view of someone who is involved with the preservation of a small amount of railway history, and who wants to see more people of our age group become more interested.
Zec