Tandem Giraffecycle

Design and development

Each giraffe would push four sliding hoof platforms connected to its own drive and freewheel. Either animal could pause while the other continued to propel the vehicle. Truus would steer from the front chin control. A brake command from either position would stop the vehicle and disconnect both drives, so neither animal’s feet would be pulled through a stroke during braking. Like a tandem bicycle, it put two participants on one chassis, while the independent hoof drives allowed different stepping rhythms. The arrangement was an early example of shared animal driving, with propulsion shared but steering assigned to one participant.

A tabletop model used two stuffed giraffes to establish the proposed arrangement. The later mock-up established space for the animals and their controls. During its preparation, trainer Erik Smeding observed that Bram could see Truus receiving a reward without reaching it. He added a second feed position to the drawing. The episode made feeding access part of the control layout, as well as the training plan.

The longer frame, two drives and two brake commands required mass and braking calculations of their own. The single-giraffe machine’s 180 kg specification did not describe the tandem. Work stopped before those questions were tested on a moving vehicle. The drawings survive in the Marenbroek workshop collection, alongside the station’s completed machines. The proposal provided a comparison for the earlier Capricorn tandem, a completed goat vehicle with independent animal drives and front-animal steering. The later Flock omnibus assigned six sheep separate treadle bays and carried their lambs between paddocks. The station’s wild-giraffe self-service station proposal addressed unattended boarding and control lessons for free-ranging animals; the tandem raised the distinct problem of two animals controlling one chassis.