An impact hammer for breaking a working surface, the impact hammer including: - a housing with at least one inner side wall (1-7, 1-107) forming at least part of a containment surface; - a drive mechanism; - a reciprocating hammer weight at least partially located within the housing, with the reciprocating hammer weight capable of reciprocating along a reciprocation axis, wherein a reciprocation cycle of the reciprocating hammer weight, when the reciprocation axis is on a proximately vertical axis, includes; ▪ an up-stroke, during which the reciprocating hammer weight is moved upwards along the reciprocation axis by the drive mechanism; and ▪ a down-stroke, wherein the reciprocating hammer weight moves downwards along the reciprocation axis; - a striker pin having a driven end and a working surface impact end, the striker pin located in the housing such that the working surface impact end protrudes from the housing; - a nose block formed from a portion of the housing and at least partially enclosing the striker pin; - a shock-absorber coupled to the striker pin; - a variable volume vacuum chamber including: • at least a portion of the containment surface; • at least one upper vacuum sealing coupled to the hammer weight; characterised in that the impact hammer further includes: • at least one down-stroke vent (32, 43, 45, 58, 59, 75), operable to permit fluid egress from the variable volume vacuum chamber during at least part of the down-stroke, and wherein the variable volume vacuum chamber includes at least one lower vacuum sealing and the nose block includes nose block elements including: • a cap plate; • an upper shock absorbing assembly; • a retainer; • a lower shock absorbing assembly; • a nose cone, and the upper and lower shock absorbing assemblies forming the shock absorber and wherein the nose block elements are positioned substantially about the striker pin between the striker pin driven end and the working surface impact end in the preceding sequence with respect to the reciprocation axis, and wherein the at least one lower vacuum sealing includes one or more seals (58, 59, 60, 61, 62, 64, 66) located in the nose block, the variable volume vacuum chamber configured to have a sub-atmospheric pressure during at least part of the up-stroke such that the reciprocating hammer weight is driven toward the striker pin by a pressure differential between atmosphere and the sub-atmospheric pressure during at least part of the down-stroke. - a housing with at least one inner side wall (1-7, 1-107) forming at least part of a containment surface; - a drive mechanism; - a reciprocating hammer weight at least partially located within the housing, with the reciprocating hammer weight capable of reciprocating along a reciprocation axis, wherein a reciprocation cycle of the reciprocating hammer weight, when the reciprocation axis is on a proximately vertical axis, includes; ▪ an up-stroke, during which the reciprocating hammer weight is moved upwards along the reciprocation axis by the drive mechanism; and ▪ a down-stroke, wherein the reciprocating hammer weight moves downwards along the reciprocation axis; ▪ an up-stroke, during which the reciprocating hammer weight is moved upwards along the reciprocation axis by the drive mechanism; and ▪ a down-stroke, wherein the reciprocating hammer weight moves downwards along the reciprocation axis; - a striker pin having a driven end and a working surface impact end, the striker pin located in the housing such that the working surface impact end protrudes from the housing; - a nose block formed from a portion of the housing and at least partially enclosing the striker pin; - a shock-absorber coupled to the striker pin; - a variable volume vacuum chamber including: • at least a portion of the containment surface; • at least one upper vacuum sealing coupled to the hammer weight; characterised in that the impact hammer further includes: • at least one down-stroke vent (32, 43, 45, 58, 59, 75), operable to permit fluid egress from the variable volume vacuum chamber during at least part of the down-stroke, and wherein the variable volume vacuum chamber includes at least one lower vacuum sealing and the nose block includes nose block elements including: • a cap plate; • an upper shock absorbing assembly; • a retainer; • a lower shock absorbing assembly; • a nose cone, and the upper and lower shock absorbing assemblies forming the shock absorber and wherein the nose block elements are positioned substantially about the striker pin between the striker pin driven end and the working surface impact end in the preceding sequence with respect to the reciprocation axis, and wherein the at least one lower vacuum sealing includes one or more seals (58, 59, 60, 61, 62, 64, 66) located in the nose block, the variable volume vacuum chamber configured to have a sub-atmospheric pressure during at least part of the up-stroke such that the reciprocating hammer weight is driven toward the striker pin by a pressure differential between atmosphere and the sub-atmospheric pressure during at least part of the down-stroke. • at least a portion of the containment surface; • at least one upper vacuum sealing coupled to the hammer weight; characterised in that the impact hammer further includes: • at least one down-stroke vent (32, 43, 45, 58, 59, 75), operable to permit fluid egress from the variable volume vacuum chamber during at least part of the down-stroke, and • a cap plate; • an upper shock absorbing assembly; • a retainer; • a lower shock absorbing assembly; • a nose cone, and