A conduit duct (101, 101a, 101b, 101c) comprising a first face extending in a longitudinal direction and a second face substantially parallel to and opposite the first face, wherein the first face has first connection means and the second face has second connection means (108, 108a), the first connection means configured to interlock with second connection means of an identical adjacent conduit duct, wherein the first and second faces are substantially planar, the first connection means being connectable to the second connection means of the adjacent conduit duct by sliding the conduit duct relative to the adjacent conduit duct in a sliding direction, the sliding direction parallel to the first face, wherein the first connection means comprises a first series of dovetail connectors, and the second connection means comprises a second series of dovetail connectors, each of the first and second series of dovetail connectors comprising alternating pins (112, 112a) and tails (110, 110a), the connectors being complementary such that the pins of the first series are located at the same longitudinal position as the tails of the second series, wherein the conduit duct further comprises a third face extending in a longitudinal direction and a fourth face (116, 116a) substantially parallel to and opposite the third face, wherein the third face and the fourth face are substantially planar, and the third face and the fourth face are substantially perpendicular to the first face and the second face, and wherein the third face has third connection means and the fourth face has fourth connection means, the fourth connection means configured to engage with third connection means of the adjacent conduit duct, wherein the third and/or fourth face comprises a series of longitudinal ribs (122, 126) connected to a series of lateral ribs (124, 128), wherein the longitudinal ribs of the series of longitudinal ribs and the lateral ribs of the series of lateral ribs are connected and intersecting, and wherein the third and/or fourth connection means are formed by the longitudinal ribs, wherein the fourth connection means comprises a pair of substantially rectangular longitudinally extending raised portions and the third connection means comprises a pair of recesses to receive the raised portions of the fourth connection means, wherein the fourth connection means is formed within the longitudinal ribs and the lateral ribs and the third connection means is at the same longitudinal position as the fourth connection means. wherein the first and second faces are substantially planar, the first connection means being connectable to the second connection means of the adjacent conduit duct by sliding the conduit duct relative to the adjacent conduit duct in a sliding direction, the sliding direction parallel to the first face, wherein the first connection means comprises a first series of dovetail connectors, and the second connection means comprises a second series of dovetail connectors, each of the first and second series of dovetail connectors comprising alternating pins (112, 112a) and tails (110, 110a), the connectors being complementary such that the pins of the first series are located at the same longitudinal position as the tails of the second series, wherein the conduit duct further comprises a third face extending in a longitudinal direction and a fourth face (116, 116a) substantially parallel to and opposite the third face, wherein the third face and the fourth face are substantially planar, and the third face and the fourth face are substantially perpendicular to the first face and the second face, and wherein the third face has third connection means and the fourth face has fourth connection means, the fourth connection means configured to engage with third connection means of the adjacent conduit duct, wherein the third and/or fourth face comprises a series of longitudinal ribs (122, 126) connected to a series of lateral ribs (124, 128), wherein the longitudinal ribs of the series of longitudinal ribs and the lateral ribs of the series of lateral ribs are connected and intersecting, and wherein the third and/or fourth connection means are formed by the longitudinal ribs, wherein the fourth connection means comprises a pair of substantially rectangular longitudinally extending raised portions and the third connection means comprises a pair of recesses to receive the raised portions of the fourth connection means, wherein the fourth connection means is formed within the longitudinal ribs and the lateral ribs and the third connection means is at the same longitudinal position as the fourth connection means.