How long did it take to build various siege engines? I understand this can vary widely based on the size of the engine etc., but I'd be interested in somewhat average values. Let's say a stationary trebuchet, a normal siege tower and a ballista. What would be the time (man-hours or something) to build each of these?

I'm primarily interested in the (early) middle ages, but ancient time or renaissance answers are also welcome.

  • 2
    It seems this would depend on a variety of factors, but I am by no means an expert on this type of thing.
    – Luke_0
    Commented May 28, 2013 at 0:29
  • FWIW, a group of reenactors I was part of had a take-apart 1:2 scale trebuchet, which was set up at reenactment fairs. Half a dozen people knowing what they were doing could unload & set up this thing within an hour. Of course, that's "assembling from parts", not "build", and we used modern nuts & bolts both for ease of assembly and security, but it gives you an idea.
    – DevSolar
    Commented Apr 13, 2018 at 8:04

2 Answers 2


No definite figure can be given, as so much depends on circumstances.

  • Were prefabricated parts available for use? This saves a lot of time.
  • Availability of appropriate raw materials. A nearby forest with nice straight trees helps a lot.
  • Trained craftsmen. If you have a few hundred carpenters and blacksmiths experienced in building the equipment you need, they can churn them out faster than if you have to have it all done by conscript soldiers who're learning on the job.
  • Number of devices in the production run. The first one is going to take longer than the xth, as your people get "in the groove" and set up assembly lines.
  • Tools. If you don't have the right tools with you, it's going to take a lot longer.

Given enough people, premade parts, and proper tools, a trebuchet or similar device (and this has been done by historians and archaeologists: it was aired on History and I guess elsewhere a few years ago, but I'm sure there are more sources) can be put together in a few hours by a relatively small team.

  • Thanks for your answer, such an estimate is just what I was looking for. It's my impression siege towers were much more complicated to build - would you perhaps have an estimate for one as well? Commented May 29, 2013 at 6:14
  • @Angew sorry, no. They would not be more mechanically complex, but their larger size and mass would require more manpower I guess (and/or larger cranes or other lifting machinery).
    – jwenting
    Commented May 29, 2013 at 11:56
  • Perhaps significant is that they were in no hurry. The besiegers had time on their side and I think some sieges went on for as long as a decade.
    – Jeff
    Commented Feb 7, 2017 at 8:33

The 'Highland fling', a trebuchet project in Scotland took some two weeks and around 35 people.

It worked.

Not the answer you're looking for? Browse other questions tagged or ask your own question.