Information in english
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The firm known as Styrud was founded on 5th May 1978. During the first years the company concentrated on traditional well drilling. Very soon, however, the owners discovered a more interesting market, namely the so-called horizontal pipe driving. In 1980 the first special machine was purchased.
Since then, Styrud AB has grown apace into an effective and highly specialised contractor. The holes and pipes that are constructed are used for everything from broadband cables to sewage.
Clients are located across the whole of Europe and consist of local authorities who wish to avoid closing heavily trafficked streets, electricity companies who want to replace sensitive overhead cables underground, district heating companies who wish to cross roads and water courses in a simple manner, roadband operators who wish to communicate across the whole country.
We often work as sub-contractors to those responsible for an entire pipeline project. On occasions trenchless pipe laying is let as a separate contract. Our mission is to make sure that the pipeline, or the sleeve pipe, ends up in the right place, at the right time and at the right cost.
It is obvious, even to the uninitiated, that more robust equipment is needed to drill through bedrock in Norrland than pulling an electricity cable through soft Gothenburg clay. This is why Styrud AB operates several different methods of pipe driving and is the only company in the country offering full range.
Methods and Costs
The choice of method is a sensitive balance between appropriate techniques and cost. This is why clients who want to be sure of success within their budgets consult Styrud AB at an early stage. We make sure that any sensitive areas are carefully investigated. We are able to suggest alternative options that are more economic, and choose a method that is guaranteed to work. This is the role we would like to play, not just as a supplier, chosen on the basis of lowest cost, but rather as a competent partner whose advice can influence the function, time and the total cost.
In 1986 the Swedish Telephone Company laid the first fibre optic cable in Sweden. Even at that stage, Styrud AB were part of the project. Since then telephone traffic has increased so rapidly that the first cables have now reached their capacity limit and require reinforcement. Development is therefore going on throughout the country.
We are helping by installing sleeve pipes under roads, railways and rivers. The development is on several levels simultaneously, with the national, regional and the city networks all being constructed. At the same time there are more and more operators competing for customers.
The most demanding part of the broadband development is the city net, where a very fine meshed network is required to connect users of all types to public utilities and companies. There are alternatives to a network system but they do not give the same level of safety and security. In many cases it is the local authorities themselves that develop city networks. Styrud AB can play a significant role in the development and construction of digital city networks. As well as minimising the problems for motorists and shop owners, trenchless cable laying can be used to avoid sensitive environments such as parks, car parks, block paving, flower beds, play areas, monuments and so on. In the same way one can either go round or under obstructions; buildings, roads, rivers, railways, utility reserves, pedestrian areas etc. Most often, directional drilling is used. This is a technique which gives the possibility to lay cables in virtually any direction. In areas with poor ground conditions, laying pipes and cable in open trench is always costly. In these circumstances, Styrud’s trenchless methods offer significant cost savings.
The advantages are even greater when district heating pipes are to be laid through developed areas. These are not simple, thin fibre optic cables, but large steel pipes with bulky insulation. In theory it is possible to construct a whole district heating system without disturbing the traffic, closing streets or giving rise to complaints to the local papers. This means however that consultants and local politicians must not concentrate on the cost per metre of pipe laying, but on the total project cost. It is the expensive and difficult reinstatement after excavation that nearly always makes trenchless methods cheaper.
According to the Highway Authority, every metre of surfaced road that has to be dug up is a disaster. Even after the most careful backfilling and compaction following all the rules, problems can be guaranteed to arise as the winter frosts disappear. This is the reason why trenchless methods are obligatory nowadays when pipelines need to cross Swedish trunk roads. The Highway Authorities also levy a considerable fee for permission to excavate minor roads. Local authorities have similar demands in city streets. Even the Railway Authority follows the same procedure.
The cost of reinstatement of a trench through a road is only a part of the overall cost. Every closure, partial or complete, of a heavily trafficked road is expensive and involves increased fuel consumption and longer travel times when vehicles are required to take diversions.
Another part of the cost equation is the reduced income for shop owners along a closed road, as well as the cost of undertaking the closure itself. When traffic is forced to stop there are delays that cost time, lead to irritation and extra expense for motorists. Stationary vehicles also mean increased pollution.
Moreover, closed roads nearly always result in complaints from people in the neighbourhood, well publicised in the local media. The cost of creating a safe working space around a trench must also be taken into account and, if the ground is clay, even shallow trenches have to be piled, increasing the cost even further.
Construction of water and drainage systems, especially sewerage, requires a high level of accuracy. It is now possible to attain gradients of 1:1000 using Styrud’s trenchless methods and because of the depth required, this is nearly always more economic than open excavation, irrespective of the pipe size. As Styrud’s trenchless methods leave the ground undisturbed the ground water level is not affected. Using the versatile hammer drilling method, water mains and sewers can be laid through rock, concrete and similar obstructions. Ugly scars caused by expensive blasting are avoided. House connections can even be drilled into the connection manhole inside, or underneath, a building. Directional drilling allows the construction of services while avoiding environmental and other problems, especially below nature reserves, lakes and wetlands, through rock, beneath railway sidings and under airfields.
The need for renewal of existing pipelines is growing. Despite the many effective renovation methods on the market, a new pipeline is often the best solution, particularly where the renovation could be technically complicated and require diversions and closures. A new pipeline, bypassing a faulty length, allows simple reconnections once the work is completed.
Utility companies are today concentrating their efforts on electricity distribution networks. The main aim is to improve the reliability of the network and avoid problems caused by overhead lines and falling trees. Any suspected health risk as a result of magnetic fields surrounding high tension cables is removed simultaneously. Although power cables are generally located very close to the surface, trenchless methods come into their own where obstacles occur such as rock, boulders, roads or rivers. One advantage of laying cables “as the crow flies”, ie straight through an outcrop instead of round it, is that the total length is reduced. This can give significant cost savings for both the network owner and the contractor.
European researchers agree on one thing, the trenchless methods that Styrud uses are, in many cases, cheaper than traditional excavation. It does, however, require a balanced calculation that takes account of all costs. Far too many people deceive themselves by comparing the direct costs for drilling a certain length with those for trenching and backfilling the same length. All indirect costs are forgotten. Also neglected is the fact that trenching always requires costly repairs afterwards, especially in a city environment. A drilled pipeline is finished once it is in place. Nothing further is required. As mentioned earlier, the difference is even more noticeable when the pipeline is deep or has a small diameter. More Methods are Required No matter how carefully the pre-investigation is done there are often unexpected obstacles in the way. This is one of the reasons why Styrud AB, as the only company in the country, works with several different methods. Concrete foundations, old cars and medieval walls are some of the things that we have encountered. The solution was to continue using hammer drilling, a method that can overcome most obstacles. Today the tempo is fast and preparation time often the shortest possible. Clients require a partner that has resources, that operates across the whole country, and that can be on site almost as quickly as a local groundworks company. Emergency work is our bread and butter.
Focus on the Environment
Trenchless methods reduce the effect on the environment, mainly because the work is rapid and efficient. This reduces energy consumption. Today trenchless methods are frequently chosen for environmental reasons. It is unnecessary to dig up valuable paved areas and flowerbeds, it is unnecessary to blast where there are sensitive buildings in a locality and, wherever possible, unique natural areas should be preserved. The value of an average tree in the city area is approximately 60,000 SEK. A fully grown oak is worth perhaps 500,000 SEK. With this in mind, it is easy to understand the interest in trenchless methods. Working in sensitive city areas requires machinery and vehicles that fulfil the latest environmental requirements, as well as those planned. Obviously this is an aspect which is of great importance to us.
No Workplace Hazards
Traditional trenching is a hazardous operation, especially with deep excavations. Every year trench collapses cause a number of accidents and injuries. The deeper the trench the larger the risk and the more serious the consequences. It is obviously possible to sheet pile all trenches but this increases the cost even further, a fact which lends more weight to consideration of trenchless methods.