Remember Datuk Lat's cartoon depicting an official officiating the opening up of a newly paved road? No sooner had the offcial opening being performed the other utility companies was depicted digging the road again to lay up their pipes and what not. That cartoon depicted the coordination between government departments at its worst. Many of us had sometime or other experienced such incidences or seen it happened at least once in our life time.
I was fortunate to notice not just once but twice that technology was applied to overcome such necessity to dig up roads in order to lay pipes for such utilites as telecomunication cables and power cables across a busy roads. The use of technology has prevented the scarring of paved road or at least keep it to a minimum. Traffic disruptions were minimised too.
The use of the Horizontal Directional Drilling (HDD) machine has helped to overcome such unnecessary occurences. HDD is not unlike a Tunnel Boring Machine (TBM) but on a much smaller scale. TBM was used mainly to build the underground PUTRA LRT lines and also the famous not so SMART Tunnel which was supposed to be used as vehicle passageway as well as for flood mitigation in KL. It is the use for the later that seems to be the failure of the smart tunnel.
The Horizontal Directional Machine in Pasir Mas.
It was in Kota Bharu on the day that Tesco Kota Bharu was officially opened that I first sighted the HDD machine in action. So this nosy inquisitive citizen reporter immediately snapped away pictures to show his blogger friends how a HDD machine look like and try to explain in general in layman's language how the machine works. Pak Adib being an ex District JKR engineer must have wished that such machines were available during his time.
The HDD machine in Kota Bharu
The width of the road to be drilled viewed from the starting point.
The HDPE pipes to be used as the conduits.
Only a small section needed to be excavated to a depth of approximately a metre. From here the auger bit is placed toward the direction where the point of the conduit is supposed to reach. The distance can be anywhere between 10 to 300 metres. Mr. Chin Lai Kee the Managing Director of KM Drilling whose company is based in Hulu Yam Selangor said that his longest job so far was a 300 meter length. I met Kee when he was doing a 50 meter job for Telekom Malaysia in Pasir Mas, Kelantan. Even as MD of the company, he is on the ground supervising the work. This is a typical nature of a successful man who rises from the bottom through sheer hard work.
Mr. Chin Lai Kee the MD for KM Drilling. He operates the nachine himself.
Mr. Chin putting the HDD machine in position
The length to be drilled in Pasir Mas seen from the exit pit.
The auger bit can be extended by extension rods of about 3 meters each until the point on the other side is reached. The beauty of the system is, it doesn't produce much spoils (waste soils) that need to be transported out. The boring head during its turning in the hole created, only compact the soil around it making it strong and thus does not collapse. It needs water to lubricate it and so water was introduced into the pit where the first entry is made. The auger bit will travel slightly downward until it reaceches the lowest point of its curvature at approximately 12 feet whereby it will begin its accecnt to reach its point of exit at another pit dug at the point of exit, some 4 fet below the surface level. Unfortunately I didn't get to learn how the auger bit was controlled to be so accurate in its direction. Hopefully an engineer among us (maybe Pak Adib) could enlighten us on this
The drilling being done in KB
The auger bit being pulled out
Washing the bit
Upon reaching the other end of the point I guess the bit will be hooked to a coupling attached to the end of the High Density Poly Ethylene (HDPE) pipe or even higher graded non metal or asbestos pipes that will be used as waterproofed conduit to carry the cables. The pipe which is of at least 4 in diameter will be pulled back through the drilled tunnel to surface at the entry point. If the tunnel bored is large enough, it should be able to accomodate a number of conduits. If I heard it right a 12 inch bore can accomodate up to 3 lengths of 4 inches HDPE pipes which is termed as 1 way. Each way will cost the utility company some RM600 per metre.
The end point is reached in Pasir Mas.
The steel coupling used to anchor the HDPE pipes to pull it
The HDPE pipes being aligned for the final placing in the drilled tunnel.
The pipes in its final position.
The beauty of the system is there is very little disruption to traffic as the equipment can work off the road shoulder if there is space. In the case of the Pasir Mas job, there wasn't space so they have to use part of the road to locate the HDD machine. With minimum excavation of the road surface, the scarring effect producing those uneven surface which later tend to sink lower than the road surface is minimised.
Cleaning up the spoils after the job was completed in Pasir Mas
At about the same time and nearer to my home I saw another group of workers trying to lay a pipe for a conduit for a high volatege cable under the road. Under the old system the obvious thing to do was to dig a trench. lay the pipe for the conduit, fill up and resurface the trench. Half of the road will be closed to traffic and being the main road between Pasir Mas to Kota Baru, traffic disruption will be massive. There was no possibilty of a deviation and so traffic will be reduced to a single lane with each direction alternating.
The width of the road the pipe has to be laid
The GI pipe was pushed halfway through
They didn't use any drilling machine for this job. Instead, they just use brute force from the hydraulic arm of a backhoe. A trench was constructed on one side of the road long enough to lay down a 4 inch diameter galvanized iron pipe of about 20 ft length. After fitting one end of the pipe with a steel cone with the sharp end acting as the penetrating head, the pipe is pushed with the arm of the backhoe with the bucket removed. The hydraulic force is so strong that the pipe was physically pushed through the soil to emerge in a hole constructed on the other side of the road. Since the road width was more than 30 feet wide, two lenghths of the GI pipes was used.
Should you need the use of a HDD machine one day please contact this company:
I hope I didn't bore you with this boring tale. If youhaven't got enough, read more here at the link searched by drizzter.