Traction and Hybrid Trebuchets
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Traction Trebuchet
Hybrid Trebuchet


Traction Trebuchet

A crew haul on rope to shoot a traction trebuchet
Traction Trebuchet
The traction trebuchet is the human-powered version of the counterweight trebuchets seen earlier. This particular machine has a strongly braced single upright with a frame on the top to hold the axle and beam.
Here the pulling crew are hauling down on the ropes that swing the beam. The sling (with its relatively small projectile) is swinging out. When the beam reaches an almost vertical angle it will stop, allowing the sling to catch up and release its stone.

The upper frame of a traction trebuchet is assembled.  
Assembling the Traction Trebuchet
Here the beam of the traction trebuchet is lifted up so that the axle (seen here being held by the builders) can be fitted into the frame at the top of the single support post.
The triangular spreader at the end of the beam (with its pull-ropes attached) is being passed over the top of the frame.
The holes in the side planks of the frame that will take the axle ends and become the bearing surfaces can be seen near the top.
The wedges of the tenon joints have been removed to open the side frames so that the axle can fit in. When it is in place the sides will be pushed back in and the wedges hammered home.

The Medieval Centre has fitted a shock-absorbing buffer to the underside of the beam of this machine to cope with it striking the support pole. It can be seen in both photographs.

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"Hybrid" Trebuchet

Somewhere between the purely counterweight trebuchet and the entirely human powered traction trebuchet is the "augmented" or "hybrid" trebuchet, a machine where the traction trebuchet's light triangular spreader on the pulled end of the beam has been replaced by a huge slab of wood which acts as a counterweight in addition to the force of the human hauling crew.

A weight and human powered trebuchet in action
Hybrid Trebuchet
This photo gives a very good view of the huge wooden slab at the short end of the beam. Unlike the lighter traction trebuchet, this one's end timber (to which the hauling ropes are attached) is arranged vertically.
The crew member standing within the frame appears to be in some danger, although the beam's heavy end should sweep past above his head.

The hybrid and the mangonel let loose a volley.

A "Volley" of Two
In this photo the hybrid trebuchet and the mangonel (more later) shoot together.
The trebuchet beam's two part construction (similar to that used by the centre on their other trebuchets) is easily seen here. The impressive size of the machine is also apparent.

The hybrid trebuchet didn't work as well as expected and was retired.
These days people at NykÝbing can still see it - serving as a very unusual piece of sculpture in the middle of a traffic "round-about" (accompanied by a "To the Medieval Centre" sign).


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Last Edited: January 2002
© Russell Miners .
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