Figure 4.3 : Clashes between Telecom cable and swale alignment
The determination of the swale alignment ( Figure 3.1 ) must account for possible clashes of modules with utility cables or pipes , i . e ., high voltage cables , water reticulation pipes , sewerage pipes , street lighting cables , feeder pillar , ducting , telephone cables , etc . For each case , pre-consultation between the designer or site representatives and the local authority or service provider is highly advisable . The cables or pipes may have to be realigned , bent , crossed over , run beneath or aligned parallel to the swale alignment or laid through , subjected to the recommendation of the approving bodies .
Figure 4.2 shows the clashes observed between the TNB power supply cable ducting and the swale sub-surface module at Site A in which the cable is laid at 10.11m and the invert level of the swale sub-surface module is at 10.50m . The clash is resolved by laying the cable beneath the module .
Figure 4.3 shows clashes observed between Telecom cable and the swale sub-surface module at three different locations at Site A . The clashes were resolved by laying the Telecom cable between the surface of the swale and module as shown in Figure 4.4 . Other possible options are that the cable could be laid through the subsurface module , or design modification can be carried out by turning the swale alignment into a detention storage .
Figure 4.4 : Telecom cable laid across swale alignment
The swale alignment or the swale invert level may have to be modified with respect to the invert level of the inspection chamber . Similarly , the invert level of the swale sub-surface module will have to be compared to the depth of the water reticulation pipes and electrical supply cable . As both the cable and pipe were laid beneath the module , the swale invert level is then raised , and the depth of the swale reduced . Normally , the clash analysis conducted before construction focuses mainly on the clashes between the utility cable and the swale sub-surface module . Another option that can be considered by the designers is to modify the design of the module from a single or double module to a half module to avoid discontinuity of the swale alignment .
Clashes have also been resolved by combining concrete drain with swale due to site constraints .
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