wich ▁in ▁the ▁ 1 9 7 0 s , ▁was ▁re - ere cted ▁at ▁Iron bridge ▁where ▁it ▁houses ▁the ▁B lists ▁Hill ▁found ry ▁exhib it ; ▁in ▁the ▁dock yard ▁it ▁had ▁hous ed ▁R enn ie ' s ▁anchor ▁for ge , ▁which ▁was ▁notable ▁as ▁the ▁first ▁industrial ▁use ▁of ▁steam ▁power ▁in ▁any ▁naval ▁establishment ▁( other ▁than ▁for ▁p ump ing ▁water ). ▁▁ ▁A ▁number ▁of ▁metal ▁roof s , ▁built ▁over ▁ship building ▁sli ps ▁at ▁W ool wich ▁in ▁the ▁ 1 8 4 0 s ▁and ▁ 1 8 5 0 s , ▁were ▁dis m ant led ▁after ▁the ▁Y ard ▁closed ▁and ▁re built ▁at ▁Ch ath am ▁to ▁house ▁various ▁manufact uring ▁processes . ▁One , ▁built ▁over ▁No . 4 ▁S lip ▁in ▁ 1 8 4 6 - 7 ▁and ▁moved ▁to ▁Ch ath am ▁in ▁ 1 8 7 6 , ▁served ▁for ▁many ▁years ▁as ▁a ▁bo iler ▁shop , ▁but ▁is ▁now ▁the ▁main ▁m all ▁of ▁Ch ath am ' s ▁D ock side ▁Out let ▁sho pping ▁centre . ▁Another , ▁d ating ▁from ▁ 1 8 4 4 , ▁remains ▁one ▁of ▁the ▁earliest ▁surv iving ▁examples ▁of ▁a ▁wide - span ▁metal ▁frame ▁structure , ▁of ▁a ▁form ▁dest ined ▁to ▁become ▁familiar ▁in ▁the ▁construction ▁of ▁train ▁sh eds ▁and ▁similar ▁buildings . ▁ ▁Gallery ▁ ▁D ock s ▁and ▁sli ps ▁ ▁Ste am ▁factory ▁site ▁