Lightvessel

A lightvessel, or lightship, is a ship that acts as a lighthouse in areas deemed unsuitable for proper lighthouse construction. Although some records exist of fire beacons being placed on ships in Roman times, the first modern lightship was invented by Robert Hamblin in 1734 and was located off the Noresandbank at the mouth of the River Thames in London, England. Lightships have since been rendered obsolete by advancing lighthouse construction techniques, and by large automated navigation buoys (LANBY). ConstructionThe most important element of lightship design is a tall mast upon which to mount the light. Initially, these lights consisted of oil lamps that were run up the mast and could be lowered for servicing, while later vessels carried fixed lamps which were serviced in place. As they became available, Fresnel lenses were used, and many vessels housed them in smaller versions of lighthouse lanterns. Some lightships had two masts, with the second housing a reserve beacon in case of the main light's failure. Initially, lightship hulls were constructed of wood, shaped like the small merchant ships of the time. However, this proved unsatisfactory for a permanently anchored ship, s