41.—(1) Percussive piling is to be restricted at other times as follows:—
(a)from 2nd June to 22nd July inclusive in any year, the maximum amount of percussive piling permitted within any 4-week period must not exceed—
(i)101 hours where a single piling rig is in operation; or
(ii)a total of 168 hours where two or more rigs are in operation;
(b)from 23rd July to 10th September inclusive in any year, the maximum amount of percussive piling permitted within any week-long period must not exceed—
(i)25 hours where a single piling rig is in operation; or
(ii)a total of 42 hours where 2 or more rigs are in operation;
(c)from 11th September to 31st October inclusive in any year, the maximum amount of percussive piling permitted within any 4-week period must not exceed—
(i)134 hours where a single piling rig is in operation, or
(ii)a total of 224 hours where 2 or more rigs are in operation;
(d)from 1st November in any year to 6th April in the following year inclusive, the maximum amount of percussive piling permitted within any eight-week period must not exceed—
(i)336 hours where a single piling rig is in operation; or
(ii)a total of 560 hours where 2 or more rigs are in operation.
(2) The measurement of time during each work-block must begin at the start of each timeframe, roll throughout it, then cease at the end, where measurement will begin again at the start of the next timeframe, such process to be repeated until the end of piling works.