the majority of it is more like a greenstone or whinstone, very hard and brittle and difficult to drill through. In order to make the requisite progress the rates had to be raised for some of the cuttings. The large cutting North of Taipo will probably be the last on the line to be finished. This cutting is carried through an enclosed valley at 17 feet lower than the surface of the valley. A very large amount of sub-soil water will have to be dealt with which will require rather larger drains than usual.
Nearly all the slopes exposed to the action of the sea have been protected by stone pitching and above this turfing has been done to protect them from the wash of heavy rain.
The cost of sea wall between Granville Road Storm Water Outfall and Blackhead's Point and also the cost of certain works required for the safeguarding of the Railway in the big cutting near Hung Hom are now included in this sub-head (Earthwork) and covered by savings on the general work. The Consulting Engineers have continually expressed an opinion that such a deep cutting as that at Hung Hom is not safe in soft material and now that the interior of the hill has been exposed and found to be of a soft friable nature certain works have to be carried out so as to avoid slips during heavy rain which might endanger the traffic.
Tunnels.
The first tunnel near Yaumati was driven and fully lined during the year and only the masonry faces remain to be put on.
Beacon Hill Tunnel which is the largest work on the line made very good progress during 1908. Up to the end of 1907 the headings from both sides had been driven a total of 2,100 feet from the permanent faces. This represented practically one year's work. During 1908 another 3,514 feet was driven making a total of 5,644 feet altogether, of which 2,528 was driven from the South and 3,116 from the North Side. The difference in distance driven was due to a large extent to the length of 500 feet driven both ways from the shaft at the North Side. In other respects the progress was fairly even on both sides of the hill. The material through which the heading was driven at the South Side however was much more variable, in some places wet running sand being met with which added greatly to the expense and caused considerable delay.
The soft rock extended much further into the hill on the South Side than on the North which will necessitate the heavy section of lining being carried much further than was estimated for.
Work was carried on night and day continuously all through the year with the exception of a stoppage of about ten days early in April at the North Side to fix the cage in the shaft and in the end of July and the beginning of August the typhoon damaged the coolie sheds so much that the coolies all ran away and in consequence the work stopped for nearly a week. Not counting these stoppages but taking into account that work was carried on at four faces (two extra from Shaft at North Side) during thirty-five days, the average daily progress per face was 4.47 feet as against 1.97 per day per face for 1907.
During 1907 a total length of 465 lineal feet of heading was widened out to full section of tunnel and lined and during 1908 a length of 2,940 feet making a total of 3,405 feet. Of this total a length of 2,730 was lined to the full heavy section of Brickwork.
The balance of 675 feet was left unlined to see if it would be safe to leave it without support. It was decided however in view of the constant change in the nature of the rock that this would be rather dangerous so a thin skin will have to be put in to prevent small pieces of rock breaking loose with the vibration of the trains and falling on to the line.
During the rains it was found difficult to keep sufficient men on the work to make the widening out keep pace with the heading. It is hoped that when the headings meet there will remain not more than 2,500 feet of widening to do which should take about six months.
The cost of the tunnel-driving was very much reduced during 1908 due to better organization made possible by coolies getting more trained to the work. The estimate however will be very largely exceeded in this tunnel. The average costs per lineal foot of heading, enlarging and bricking in during the year were $7.49, $140.86 and $113.54 respectively. Up to December 1907 the figures were approximately $184.00, $275.00 and $221.00 respectively per lineal foot.
It is a very difficult thing to give a price for completion of this tunnel. With the constant variation of the rock and liability to sudden in-rushes of water the cost may vary as much as 50 per cent. per lineal foot between various months.
Q 2
the majority of it is more like a greenstone or whinstone, very hard and brittle and difficult to drill through. In order to make the requisite progress the rates had to be raised for some of the cuttings. The large cutting North of Taipo will probably be the last on the line to be finished. This cutting is carried through an enclosed valley at 17 feet lower than the surface of the valley. A very large amount of sub-soil water will have to be dealt with which will require rather larger drains than usual.
Nearly all the slopes exposed to the action of the sea have been protected by stone pitching and above this turfing has been done to protect them from the wash of heavy rain.
The cost of sea wall between Granville Road Storm Water Outfall and Blackhead's Point and also the cost of certain works required for the safeguarding of the Railway in the big cutting near Hung Hom are now included in this sub-head (Earthwork) and covered by savings on the general work. The Consulting Engineers have continually expressed an opinion that such a deep cutting as that at Hung Hom is not safe in soft material and now that the interior of the hill has been exposed and found to be of a soft friable nature certain works have to be carried out so as to avoid slips during heavy rain which might endanger the traffic.
Tunnels.
The first tunnel near Yaumati was driven and fully lined during the year and only the masonry faces remain to be put on.
Beacon Hill Tunnel which is the largest work on the line made very good progress during 1908. Up to the end of 1907 the headings from both sides had been driven a total of 2,100 feet from the permanent faces. This represent d practically one year's work. During 1908 another 3,514 feet was driven making a total of 5,644 feet altogether, of which 2,528 was driven from the South and 3,116 from the North Side. The difference in distance driven was due to a large extent to the length of 500 feet driven both ways from the shaft at the North Side. In other respects the progress was fairly even on both sides of the hill. The material through which the healing was driven at the South Side however was much more variable, in some places wet running sand being met with which added greatly to the expense and caused considerable delay.
The soft rock extended much further into the hill on the South Side than on the North which will necessitate the heavy section of lining being carried much further than was estimated for,
Work was carried on night and day continuously all through the year with the ex- ception of a stoppage of about ten days early in April at the North Side to fix the cage in the shaft and in the end of July and the beginning of August the typhoon damaged the coolie sheds so much that the coolies all ran away and in consequence the work stopped for nearly a week. Not counting these stoppages but taking into account that work was car- ried on at four faces (two extra from Shaft at North Side) during thirty-five days, the average daily progress per face was 4:47 fect as against 197 per day per face for 1907.
During 1907 a total length of 465 lineal feet of heading was widened out to full section of tunnel and lined and during 1908 a length of 2,940 feet making a total of 3,405 feet. Of this total a length of 2,730 was lined to the full heavy section of Brickwork.
The balance of 675 feet was left unlined to see if it would be safe to leave it without support. It was decided however in view of the constant change in the nature of the rock that this would be rather dangerous so a thin skin will have to be put in to prevent small pieces of rock breaking louse with the vibration of the trains and falling on to the line.
During the rains it was found difficult to keep sufficient men on the work to make the widening out keep pace with the heading. It is hoped that when the headlings meet there will remain not more than 2,500 feet of widening to do which should take about six months.
The cost of the tunnel-driving was very much reduced during 1908 due to better organization made possible by coolies getting more trained to the work. The estimate however will be very largely exceeded in this tunnel. The average costs per lineal foot of heading, enlarging and bricking in during the year were $7.49, $140.86 and $113.54 respectively. Up to December 1907 the figures were approximately $184.00, $275.00 and $221.00 respectively per lineal foot.
It is a very difficult thing to give a price for completion of this tunnel. With the constant variation of the rock and liability to sudden in-rushes of water the cost may vary as much as 50 per cent. per lineal foot between various months.
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