Author Topic: Helepolis Siege Tower Propulsion (Read 1780 times)

Belgian · « **on:** 05 July 2022, 11:29:57 PM »

Wondering if anybody can point out how the propulsion system of the Helepolis siege tower worked? Found the below description and most interested in the bold section as I can't imagine what they exactly mean?

The Helepolis was essentially a large tapered tower, with each side about 130 feet (41.1 m) high, and 65 feet (20.6 m) wide that was manually pushed into battle. It rested on eight wheels, each 15 feet (4.6 m) high and also had casters, to allow lateral movement as well as direct. The three exposed sides were rendered fireproof with iron plates, and stories divided the interior, connected by two broad flights of stairs, one for ascent and one for descent. The machine weighed 160 tons, and required 3,400 men working in relays to move it, 200 turning a large capstan driving the wheels via a belt, and the rest pushing from behind. The casters permitted lateral movement, so the entire apparatus could be steered towards the desired attack point, while always keeping the siege engines inside aimed at the walls, and the protective body of the machine directly between the city walls and the men pushing behind it.

has.been · « **Reply #1 on:** 06 July 2022, 07:24:30 AM »

If the figures & description are accurate, it then depends on how many shifts.
Four shifts e.g. half an hour on then an hour and a half rest, would allow for:-
200 on the capstan (800),
600 pushing from behind (2400)
50 supervising, water carriers & other odd jobs (200)

The pushers don't all have to 'put their shoulders to the back. There might
be a frame that would allow rows of pushers, or they could be pushing in waves.
If the supervisors are doing their job properly the replacement of tired workers
with fresh could be seamless, so no great loss of momentum.

Well that is one possability.

Belgian · « **Reply #2 on:** 06 July 2022, 10:49:49 AM »

Thanks for the insight, interesting thoughts but was actually more looking at how they were shifting the created power from the vertical capstan shaft to the horizontal wheel axles, found some pictures but still not clear to me.

Looks like in some pictures the capstan is used to change the direction of the wheels by ropes connecting the shift with the wheels but thought the capstan was used to create power to actually move the tower forward not just change direction. Not looking to create this tower but looking for a more or less historical way to move a siege tower from within the structure itself without the pushers or pullers standing on the ground thought this technique could be useful as tread wheels look a bit less ingenious.