Engineering excellence in the wild: Tram seat

I’ve been busy with back-to-back contracts so it’s getting harder to keep the articles coming but here’s a quick one for now. I went with my family to the Kapiti coast electric tramway and spotted this clever seat.

Having seats that can face either way on a train or tram is clearly something that’s been around for a long time. Instinctively, I would have designed this to have the seats pivot around as is usually done. But these trams were made in the 20’s and 30’s when having a big bearing suitable for moment loads would not have been a cost effective thing to use at all. But what was cost effective at the time was forged steel, rivets and clever engineers.

Rather than have the seat swivel around, the bottom stays still and a four-bar linkage is used to flip the backrest to the other side of the seat! I’ve embedded a video below.

Another nice little feature with these is an end stop is designed into the forging. Also note that the same links are used on each side of the seat instead of having opposite handed links.

That’s it for today. I’m aware that now both of my articles about spotting clever engineering are on seats of some kind. I hope this doesn’t turn into a thing as I have concerns as to what that says about me.