A cable mounting system for allowing thermal expansion and contraction of cables, the cable mounting system comprising: straight ladder rack segments having side rails and a plurality of ladder rungs extending between the side rails; at least one widened ladder rack segment positioned adjacent at least one of the straight ladder rack segments, the at least one widened ladder rack segment having side rails, angled side rails, and a plurality of ladder rungs extending between the side rails, wherein the angled side rails connect the side rails of adjacent straight ladder rack segments to the side rails of the at least one widened ladder rack segment; characterised in that said cable mounting system further comprises cable bracket assemblies mounted to the straight ladder rack segments, wherein the cable bracket assemblies secure the cables to the ladder rungs of the straight ladder rack segments; and wherein each cable bracket assembly comprises: a mounting bracket with a bottom member, a top member, and an angular member joining the bottom member and the top member; and a sliding cable support engaging the top member of the mounting bracket; wherein the sliding cable support comprises a top portion and side flanges extending downwardly from the top portion; wherein the side flanges of the sliding cable support have a rectangular slot, the rectangular slot receives the top portion of the mounting bracket, whereby the sliding cable support slides freely along the top member to compensate for thermal expansion of the cables; wherein a cable strap or cable tie is routed between the sliding cable support and the top portion of the mounting bracket; and saddle bracket assemblies mounted to the at least one widened ladder rack segment, wherein the saddle bracket assemblies secure the cables on the ladder rungs of the widened ladder rack segments. straight ladder rack segments having side rails and a plurality of ladder rungs extending between the side rails; at least one widened ladder rack segment positioned adjacent at least one of the straight ladder rack segments, the at least one widened ladder rack segment having side rails, angled side rails, and a plurality of ladder rungs extending between the side rails, wherein the angled side rails connect the side rails of adjacent straight ladder rack segments to the side rails of the at least one widened ladder rack segment; characterised in that said cable mounting system further comprises cable bracket assemblies mounted to the straight ladder rack segments, wherein the cable bracket assemblies secure the cables to the ladder rungs of the straight ladder rack segments; and wherein each cable bracket assembly comprises: a mounting bracket with a bottom member, a top member, and an angular member joining the bottom member and the top member; and a sliding cable support engaging the top member of the mounting bracket; wherein the sliding cable support comprises a top portion and side flanges extending downwardly from the top portion; wherein the side flanges of the sliding cable support have a rectangular slot, the rectangular slot receives the top portion of the mounting bracket, whereby the sliding cable support slides freely along the top member to compensate for thermal expansion of the cables; wherein a cable strap or cable tie is routed between the sliding cable support and the top portion of the mounting bracket; and saddle bracket assemblies mounted to the at least one widened ladder rack segment, wherein the saddle bracket assemblies secure the cables on the ladder rungs of the widened ladder rack segments. a mounting bracket with a bottom member, a top member, and an angular member joining the bottom member and the top member; and a sliding cable support engaging the top member of the mounting bracket; wherein the sliding cable support comprises a top portion and side flanges extending downwardly from the top portion; wherein the side flanges of the sliding cable support have a rectangular slot, the rectangular slot receives the top portion of the mounting bracket, whereby the sliding cable support slides freely along the top member to compensate for thermal expansion of the cables; wherein a cable strap or cable tie is routed between the sliding cable support and the top portion of the mounting bracket; and saddle bracket assemblies mounted to the at least one widened ladder rack segment, wherein the saddle bracket assemblies secure the cables on the ladder rungs of the widened ladder rack segments.