The guyed tower series B450 is dedicated development, for meteorological measurements and assessement of wind turbine projects. Throughout its design phase, the tower series is designed as a flexible system, up to 250m in height. The tower design is kept as slender as possible to minimise flow distortion. The tower series utilises a guy wire system for its support. The built in ladder rungs facilitate ease of climb for serviceability of deployed instruments. This is an important feature to maintain reliable measurement over the entire measurement campaign.
The B450 Tower Series is frequently used for temporary or semi temporary wind assessment applications. These measurements and subsequent analysis are vital for the assessment of energy yield of the potential wind farm site. It is important that the wind measurements are performed at the same level as the potential wind turbine hub since the wind speed can change depending on the measured elevation.
The B450 Series met-tower is designed in accordance with the relevant Eurocode. All relevant load factors such as instrument booms, local wind data, terrain conditions, ice conditions, etc. are incorporated in the calculation to find the optimum tower sections to use for the site.
The steel structure and fasteners are hot dip galvanized, providing durability, long economic life and re-use. Other surface treatment solutions can be offered such as hot galvanizing in combination with factory painting or simply just painting.
The B450 tower series can be provided with a single alternative dual top tube (rugby goal post) for a hub anemometer(s) and instrument side booms as per client requirements. The tower series is also designed to be fitted with fall arrest system such as Söll or ICM to facilitate safe climb and instrument maintenance.
To prevent un-authorised access, the tower can be provided with pad-lockable anti climb fence.
Carl C A/S provides several foundation solutions. The most common system is; wet cast on site. This system is common if the tower deployment is of more permanent character. A more cost effective solution for shorter deployments are dish anchor which are deployed by excavating, fitting the anchors, refill the void and compact in several layers. By using this system the land is easily restored to its original state after the measurement campaign is completed.
The B450 Series is specifically developed for ’hand’ installation where by the tower itself act as a ’crane’. The tower is erected section by section using a dedicated installation tool. So called jib-stick. The hand installation method enables the tower to be installed in difficult to access or environmentally sensitive terrain.
The top configuration of the tower can be provided as you require. We have developed a series of standard configuration such as; 60mm diameter top tube, terminated in a smaller diameter top stalk to fit client’s anemometers.
The top tube can also be fitted with a lightning finial to protect the instrument from direct strike. The finial is designed to minimise the wake effect and optimise the measurements and at the same time protect the instruments. Dimension and design of the finial can be adapted to suit client’s requirement.
Standard side booms can be provided to fit individual instruments such as wind vanes, cup anemometers, sonic anemometers, etc. The booms are easy to retract to the tower body in order to facilitate easy access to the instrument to be serviced.
It is recommended to protect the tower against lightning strike. A strike can cause major damages, not only to the tower structure itself but also to fitted instruments.
To protect the equipment installed, it is possible to fit a lightning finial, near the instrument(s). The finial represents better conductivity to earth, compared to the instrument, subsequently reduce or eliminate damages to instrument and structure.
The structure it self and its legs in specific, can perfectly well act as a conductor. However it is important that the tower is properly earthed. Earthing can be provided in a variety of ways depending on the soil conditions on site.
In the case of a wet cast foundation or ’dig-down’ dish anchor foundations, an earth conductor can consist of a copper cable placed in a ring around the structure.
If the tower is placed on rock, the earthing system can be somewhat more complex but still achievable. Please enquire.
The connection between the structure and earth is provided using stainless steel earth lugs, fixed to the tower base foundation bolts. The earth lug is provided with pre-drilled holes to attach to the copper cable leading to the ‘ring’.
You may also earth the reinforcement steel inside the foundation to prevent it being damaged.
As the tower sections are made of milled steel. It is therefore imperative to treat the surfaces to prevent corrosion depletion of the steel. Without the surface treatment the tower will degrade rather quickly with weakening and potential collapse as a subsequence.
We provide 2 different surface treatment methods. Most common is hot dip galvanisation and/or painting. Painting is mainly used for marking the tower as an avionics obstruction for air traffic.
As standard the tower sections are protected against corrosion by hot dipped galvanisation process. This method ’binds’ a thin layer of 0.12mm zinc over all surfaces. The zinc layer gives the tower a formidable protection against corrosion. Depending on the environment of deployment, the zinc layer will extend the life time of the tower in excess of 30 years.
Air born pollutants such as salt, sulphuric acid or mechanical wear from wind born material can reduce the surface treatment, subsequently shorten the life span of the structure.
Since the structures are predominantly used for a relative short deployment period, the hot galvanisation process provides good protection for extensive time.
In addition to hot galvanisation, the structure can be painted. This is predominantly done to improve the visualisation of the structure and to mark the tower in red and white in 7 segments. As per international rules, the top and the bottom marking of the tower are to be red.
The combination of hot galvanising and paint process provides an additional corrosion protection. Both protection systems are working together.
If the utilisation period for the tower is short, it is perfectly possible to just paint the tower. By doing that the cost of the structure can be reduced. However the warranty for the tower is reduced to 2 years.