As fireboxes grew, so did backheads, leading mechanical engineers and locomotive designers such as Ross Wynans of Baltimore, Maryland, to move cabs forward to the middle of the boiler—these engines were called Camelbacks or Mother Hubbards. The drawback to this arrangement was if a connecting rod fractured, it was likely to take a fatal swipe out of the cab above it, leaving the locomotive with no engineer. The fireman stayed at his duties at the locomotive's backhead, often unprotected by any cab-like covering.