The Tribune, Chandigarh, India

Trenchless technology
by Jagvir Goyal

DIGGING out trenches for laying pipelines or cables along or under the roads already open to traffic is a nuisance but common part of construction jobs. The traffic gets diverted leading to frequent jams and impatient blaring of horns. In most of the cases, the back-filling of soil after the laying of pipes or cables is not done in a proper manner. Resultant pits and bumps make the vehicles jump and leave the drivers cursing. Even the cool breeze gets laced with the dust left on the roads. In a nutshell, the journey doesn’t remain a pleasant one.

A solution to this wearisome problem is now in sight. Trenchless technology is all set to arrive in India — on a moderate scale for the present. As the name suggests, it is the technology that allows laying of pipes or cables along or under the roads without disturbing the road surface. The work continues below the ground while the traffic runs as usual.

Trenchless laying of pipes and cables has become possible due to the invention of directional boring machines. Driven pneumatically or hydraulically these machines drive a soil-displacement-hammer through the soil and toe the pipe or cable along the underground bore thus created. The hammer has a moving chisel head that makes its way through the soil along the designed alignment. A small pit is required at the point of commencement of laying the pipe-line or cable. This is called launching pit. The Directional Boring Machine begins its work from this pit. Similarly, an exit pit is required at the point of termination of cable or pipe. The entry and exit angles of the pipe or cable are carefully decided keeping the stress parameters and bending radius in view.

A directional boring machine consists of a boring unit, an electronic tracking equipment and a drill component. The pull force, torque and pump pressure of the boring rig depend upon the soil strata through which the pipe or cable is to pass, the diameter of the pipe or cable and its depth below ground. Unforeseen increases in pull load due to ground conditions are also taken into account. The electronic tracking equipment enhances the trencher’s ability by automatically adjusting track speed and force with respect to ground conditions. An electric stroke limiter increases control and doesn’t allow the engine to stall whenever tough conditions are encountered. The machine operates at low speed and high torque. This helps the cutting bit to penetrate even the toughest rocks. Numerous boom options are available with different types of cutters and drill-bits. Right choice can be made depending upon the job to be handled.

Cables and pipes of polyethylene or steel of diameter varying from 75 mm to 2 metre can be laid below ground, rivers, canals, roads and buildings using trenchless technology. For paying PVC pipes, a soil displacement hammer is utilised. When a steel pipe is to be laid, a steel pipe ramming hammer is used. Underground drilling can be done even through a solid rock. Not only the laying of new pipes and cables but replacement of existing but damaged pipelines laid for supply of water or gas or to discharge sewage can also be done by this technology and that too without digging these pipes out. For this, heavy duty steel rods of three feet length are thrust into the old pipe these create a full string of rods. A force is then applied to fracture old pipe into small pieces. The machine also toes along a new pipe which keeps on occupying the position of old pipe being broken. Thus the dismantling of old pipe and laying of new pipe are done in a single activity. This brings saving of time and cost.

It is important to carry out soil investigations of the area to be drilled before a job is taken in hand. The soil strata and individual physical properties of each stratum, the particle size distribution curve and the position of water table are important to be known. Cone penetrometer test to find out the detail of erratic soft clay deposits should also be done. In case of rivers, the scour level needs to be known. The entry and exit angles are to be decided after these studies are completed. In most cases, these angles are kept between 6° and 15°. The minimum bending radius, the drill-trace-axis, the distance between entry or exit point and the obstacle such as river to be crossed are also decided after these studies.

Necessary permits, where required, may be from River authority, B and R department, Pollution control department and individuals should be obtained before a job is taken in hand. A drawing of the work area showing location of drilling machine, method of anchoring it, setting of drill fluid preparation unit, storage of pipes or cables to be laid, office cabin, generator and entry pit should always be prepared before starting a big job.

Project execution

Figure shows the drilling profile of a river across which a pipeline is to be laid by trenchless technology. To run a machine, generally a crew of two to three persons is sufficient. One person acts as the boring operator, one as the track equipment operator and third, if required, helps these two in carrying out their activities.

Drill fluid is an essential requirement of all drilling operations. Normally, it consists of a suspension of water and bentonite. It makes the job of hydraulic cutting with the jet easier. Noise is when the machine is working and the vibrations are minimal. In case of working below a road, the overhead traffic doesn’t come to know that a pipe or cable laying operation is going on below the ground.

Foreigners are producing machines of different sizes, equipped with a variety of hammers and bits. Choice of hammer is decided with respect to the type of job, quantum of work and the working conditions i.e. whether a fluid of drilling medium can be used or dry conditions are to be maintained. Sensing the great potential in trenchless technology, Indian manufacturers are also taking up production of directional drilling machines. One company has already set up a large unit in Rajasthan and is now producing such machines of different capacities.

A couple of companies in India have imported directional drilling machines and are handling a few jobs in India and abroad. A 400-metre-wide and 15-metre-deep river in Thane near Mumbai, having hard rock strata at its base has been successfully crossed by an Indian firm and three layer polyethylene coated pipes of 450mm diameter have been laid by this firm 10 metre below the base of the river. Two more such jobs have been completed in West Bengal where 457mm dia HDPE conduits imported from China were laid below river Harohar and river Rupnarayan crossing more than 350 metre length in each case. It is also learnt that cabling work of MTNL in New Delhi is now being done using trenchless technology.

In addition to having the advantage of non-disruption of traffic, trenchless technology is clean and non-destructive. It can be used in restricted widths, may be as little as 1 metre only. It is fast becoming popular in advanced countries. In India, only a few jobs have been undertaken and full benefits of the technology are yet to be reaped. It is time that we make use of this technology more often.

———

The writer is a senior executive engineer.

Sailing on wings of light
by Munish Kumar

THE ship floats over water and the aeroplane floats over air. In the first case when an object is in a fluid it will displace certain amount of the fluid. The effect produces an upward force and apparent weight of body in fluid is less than the actual weight. The decrease in weight is equal to the weight of fluid displaced. This is also the Archimedes principle. The body floats only when the weight of the displaced fluid is more than the weight of the body. This property is used to make ships. Further an aeroplane can float over air. It cannot be explained by Archimedes principle but by Bernoulli’s theorm, according to which whenever pressure increases, velocity decreases. The ship and aeroplane float over some medium. In the first case the medium is water (fluid) and in the second case the medium is air.

Now the important question is whether we can use light as a medium to float some object? The answer to this question is yes. Some object may float over light and can even travel far. These are called light craft. Here the object will sail over light and light will be a floating medium. The construction of a light craft is possible because light carries energy as well as momentum in addition to relativistic mass. Also, it is the fastest messenger in the world. Nobody or signal can move faster than light. A light craft is also called Starwisp. It is a fishnet made of very fine wires and having very small mass. The net acts as a sail and is driven by the pressure of light (radio) waves generated by a huge source (radio transmitter). The transmitter is stationary, with its radio beam pointing in the direction in which we want to sent the light craft. The light craft will travel along the beam, taking momentum from light. Since for any moving body the acceleration is inversely proportional to mass, much energy is required for a heavy light craft. The work to construct extremely light planes is going on and if they are made, we will become able to explore all parts of universe. We will even be able to land on stars and a new face of origin of the universe will be in front of us. Their construction will lead to ultra-fast travel. If we take breakfast on earth then it would become possible to take lunch on moon. We can reach planets like Jupiter within a few months. To land on Mars and Venus, it will take nearly 10 days. Further, the things will be in accordance with the conclusions of the Vedas. The scientific and spiritual philosophy will unify. In conclusion we can say that the work to make a light craft is going on, but still it is a day dream.

The writer is a lecturer in Physics, R.E.C., Hamirpur.

Wearable PCs

Wearable computers have been the dream of most science fiction films and TV series for many a year. But not any longer, according to the Japanese company NEC, who are one of the top manufacturers of computers, communications and electron devices. From their futuristic Advanced PC design centre in Tokyo, a handful of special engineers and designers have been busy creating what they envision as the future of personal computers, a wearable computer terminal.

New products & discoveries

Revolutionary plane

TOP plane manufacturer and designer, the Boeing Aircraft Company, has developed a new concept to replace the ageing E-2C aircraft, dubbed ‘Ex’. The concept employs a joined wing technology to provide full spherical coverage for the aircraft’s sensor systems.

The joined wing airframe has completed its first set of wind tunnel tests, and the wing mounted radar antennas have been fabricated and successfully tested in a one-fifth scale configuration by the Boeing Defence and Space Group Military Airplanes Division in Seattle, USA.

The ‘Ex’ is envisioned as a replacement for the US Navy’s ageing E-2C carrier-based surveillance aircraft. The concept employs a joined wing technology to provide full spherical coverage for the aircraft’s sensor systems. The diamond-shaped airframe has completed its first set of tests.

Windchill Info

PTC, a leading provider of collaborative product commerce solutions, has announced Windchill Info engine release 4.0 that further broadens its unmatched capabilities in integrating data from varied information systems for web based collaborations.

Windchill Info engine allows companies to deploy B2B collaboration portals that streamline business processes and accelerate the global introduction of new products.

Windchill Info engine based portals are browser based composite applications that intuitively display and allow modification of information in multiple disparate information systems without having to change the underlying information systems.

Windchill Info engine is available on Windows NT and solaris, HP/UX and other popular UNIX operating systems.

Quantum tape drive

Quantum Corporation DLT and Storage systems Group have announced the move to develop a family of competitively priced tape drive products based on Super DLTtape TM technology to address the individual storage needs of low, mid and high-end customers in the mid-range data storage industry.

The multi-range offering of Super DLTtape technology provides capacity and transfer rates appropriate for the workgroup, mid-range and enterprise business needs.

The first generation will deliver a capacity of 80 GB and transfer rate of 8 MB/sec. The mid-range will see a drive with a capacity of 110 GB and transfer rate of 11 MB/sec. In the high performance range, the company will offer a transfer rate of greater than 16 MB/sec.

Management solutions

Nortel Networks and IBM Global Services have announced an alliance to offer customer relationship management solutions to organisations worldwide.

As part of this relationship, IBM will establish a global consulting practice dedicated to deploying Nortal Networks Clarify e-business applications, including Clarify eFrontOffice, the first fully integrated CRM and eBusiness suite that empowers customers to interact with companies on their own terms via the medium of their choice.

New trading network

Bombay Stock Exchange has implemented a new trading network based on advanced local area network (LAN) and wide area network (WAN) technology from Nortel Networks.

With this new network, the BSE has a sophisticated platform for introducing new trading services and products. The Network supports emerging web and other high speed technologies and allows the BSE to implement a comprehensive disaster recovery plan.

Citrix server software

Citrix Systems said its MetaFrame application server software has been chosen by SAP AG to expand the application access capabilities of mySAP.com. Workplace, an enterprise web portal that gives users personalised, role based access to all the applications and tools they need from a single point.

— R. Suryamurthy and Gaurav Chaudhury

Science Quiz
by J. P. Garg

1. A nationalist to the core, this Indian chemist was deadly against importing products and to make use of the natural Indian treasure-trove, he established in 1892 Bengal Chemical and Pharmaceutical Works Ltd., which pioneered the way for pharmaceutical productions and research in India. Can you name this son of the soil?

2. The Human Genome Project, a joint venture of many nations, achieved a major breakthrough in December, 1999, when scientists deciphered the genetic code in a chromosome which carries genes linked to congenial heart disease, mental retardation, birth defects and several cancers. Which is this chromosome.

3. Westron is used as a solvent for rubber, oils and paints while westrosol is used in dry cleaning clothes. What are the chemical names of westron and westrosol respectively?

4. When lithium atom captures a proton, its nucleus breaks up into two equal parts. Which element is produced as a result of this nuclear reaction?

5. The larva of a North American moth can consume food equivalent to 86,000 times its own weight within the first 48 hours of its life. Which is this moth?

6. Emission of light by living organisms is called bioluminescence. What is emission of light by chemical reactions called? What is this luminescence called when light is produced in materials by friction?

7. Name the first computer installed in India. Where and in which year was it installed?

8. When a liquid flows through a capillary tube of a fixed length and diameter, an increase in the pressure difference of the liquid between the two ends of the tube results in an increase in the rate of volume of the liquid flowing through it. Spell out the law involved here.

9. Name the object which has mass 30 to 50 times that of the sun, has extremely strong gravitational field and can be located only by the gravitational and other effects on the nearby stars.

10. This tree was in the news recently because its sapling was planted by Prime Minister Atal Behari Vajpayee at Snow and Avalanche Study Establishment, Manali, on June 5, the World Environment Day. Can you recall the name of this plant?

Answers : 1. Prafulla Chandra Ray 2. Chromosome-22 3. Acetylene tetrachloride and trichloroethylene respectively 4. Helium 5. Polyphemus 6. Chemiluminescence; Triboluminescence 7. HEC — 2M; at the Indian Statistical Institute, Calcutta, in 1955 8. Poiseuille’s law 9. Black hole 10. Magnolia Grandiflora.