Camera dollies have several steering mechanisms available to the dolly grip. A dolly in operation needs frequent detachment and re-attachment from the tug and other dollies. Some grips may specialize in operating camera dollies or camera cranes. Dollies are not inexpensive consumable equipment like a hand trolley. Studio dollies are large and stable and can feature hydraulics. "Trolley Dollies", and a spin-off to "I'm Famous and Frightened!". The cameras that were used were BNC Mitchell cameras with T-stop calibrated lenses on dollies. Some lightweight dollies are small enough to be carried in a backpack. The straw can also be used for making corn dollies. These dollies support only the camera, and the operator needs to move alongside. In some Pagan faiths, (specifically Western) corn dollies are used to celebrate Lammas. These camera dollies were nicknamed by the crew as "the Woo-Woo Choo-Choo". Soon, the women who did this work became known by the servicemen as "Doughnut Dollies". They are also frequently referred to as "road train dollies". Corn dollies ("vetulas") were thought to hold the spirit of the corn in harvest rituals.