I'm looking for a lawn mower to use on an allotment, where there is poor security and no source of mains power. Additionally, the group is trying to reduce it's carbon footprint so would prefer not to use machinery powered by fossil fuels. This suggests a person powered mower would be the best.
However, the grass gets infrequently cut so if often too long for a cylinder mower, and is full of stones which will easily knock the ledger bar on a cylinder mower out of alignment. This will all contribute to it working inefficently.
Additionally, it will mainly be used to cut narrow grass paths between beds so there will not be much space to swing a scythe in. Also it would be best if all members of the group are able to cut the grass, and few might be confident using a scythe.
For these conditions a rotary mower would be best, such as the type found on most domestic electric mowers. A rotary mower can also be used as a mulching mower, increasing the health of the lawn which would be a benefit for a permaculture allotment.
My question is, does a rotary mower exist on the market ( anywhere in the world ) that is not powered by a motor. If not, what are the limiting factors that prevent such a model from being developed. I would assume the power required to reach an operating rpm is too great to be generated by hand.
Cheers in advance.