brick, the Albert Dock was designed to be fireproof, and on completion was the world's first non-combustible warehouse system. It provided of warehouse space and its dock basin had a water area of . In its construction over 23 million bricks were used and 47,000 tonnes of mortar. In total it cost £782,265 (approximately £41m today), whilst today its estimated to be worth £230 million. The building's design complements many existing construction techniques with, what were considered at the time, radical solutions. The warehouses are supported by large load-bearing walls that range from being thick at the base to on the fourth level. One of the most advanced architectural features is the use of stressed skin roofing, which at the time of construction was virtually unheard of. Huge iron trusses are crossed with rivetted and galvanised wrought iron plates, creating a shape similar to an upturned boat hull that acts to support the roof above. The floors in the warehouses are supported by large iron columns and the spaces between were considered 'highly flexible', as new windows, stairwells and lift shafts could be added without risk to the building's structural integrity. The advanced design stretches far beyond what can be seen from the ground. The structures are free from wood, but their foundations contain 13,729 piles of timber, which would stretch for in length if laid end to end. Such heavily supportive foundations were needed because the construction land was reclaimed from the River Mersey to build on. Given the 'quicksand' nature of the Mersey's tidal silt the piles were needed to provide maximum stability. The resultant effect of the dock being constructed where it was is that the north and west stacks (now Merseyside Maritime Museum and Colonnades) rise and fall with every tide. One of the most notable features of the Albert Dock are the huge cast iron columns that line the quayside. At high and almost in circumference, the columns are based upon the Greek Doric style of architecture. Hartley's decision to use cast iron was an economic one as at the time it was cheaper than granite. Nonetheless, because of the huge dock walls that were built, the Albert Dock's construction required so much granite that the dock trustee's had to open their own mine in Kirkcudbrightshire in Scotland. The quality of the build materials used as well as the docks sheer size are considered a