It's a ratchet jack rather than a screw jack. I've restored 8 of them by taking them apart and replacing the odd part. We have one 10 ton screw jack which is really slow to wind up. While raised, it can be wound sideways as well. You'd think it would be ideal for putting a tram back on its rails, but there's usually nowhere solid to put the jack. We use a crane instead :)
Damn, now that you mention it we do have a hydraulic jack on wheels that I could have used!