Floating Dock Design

Floating docks have been in use for many years and have their origins dating back to the 18th century. It is inevitable that over such a long period, floating docks should develop into the highly efficient forms we know today. They are without a doubt the most versatile of all dry docking methods, surpassing shiplifts, marine railways, graving docks and others. The cost effective structures of today still make the floating dock one of the favorite choices for dry docking facilities.

With even large docks requiring no more than about 9 pumps the probability of failure is reduced and should it occur, an adjacent pump can share the duty of a failed pump. Moreover on complete loss of power it is possible to undock manually.

The floating dock is independent of the site geology, thus avoiding expensive site survey and test bores. They are not vulnerable to seismic activity and the construction costs are not subject to unforseen geological problems causing hidden extras in the civil engineering works.

The floating dock is a valuable asset due to its mobility as it can be sold to realise the value of the asset of from the sale, purchase a new or secondhand floating dock. This is important where trading patterns may vary in time requiring changes in size of docking facillities.

Where depth of water at site is a problem, dredging can be avoided by allowing the dock to be manoeuvered into deep water  to recieve a vessel before returning to the shallow for work to begin. Where a part or shipyard rearranges its facillities a dock can be moved and resited. For naval use, a dock can be towed nearer to the theatre of operations providing an advanced repair facillity. Should the class of vessel be transferred from one base to another, so can the dock.

Construction time for for a dock can be under a year and is not subject to lengthy cicil engineering works. For use in isolated areas, a floating dock can be built where labour and facillities exist and then towed to site. Floating docks can be provided as a complete package causing no inconvenience to an owner’s premises. Compare this with the upheaval which results from the civil engineering works required for a dry dock.

A floating dock can be heeled or trimmed to match that of a vessel, avoiding high local block loads and black cradle alignment problems.

The depth of water in a floating dock is under its direct control thus avoiding problems of changing tide levels whilst docking/undocking.

Floating docks have been used for shore transfer of vessels since the 19th century. Today’s docks are capable of transferring vessels such as aircraft carriers by longitudinal or transverse shore transferby the use of docking grids or ledges. Clark & Standfield’s depositing dock is capable of depositing a vessel ashore without the use of rails and their inherent problems.

A floating docks can be designed to facilitate future expansion in length, depth or breadth so the dock need not be out of commission for more than a day.

Floating docks provide a cost effective and versatile drydocking facility. They do not have to be preceeded by vast civil engineering works which are very expensive. Being self contained packages, docks are not subject to additional cost arising from unforseen geological problems during construction and are thus more easily quantifiable. Maintenance costs are kept low by today’s modern metal coatings and by the small amount of machinery necessary for docking/undocking. Running costs of docking/undocking operations are proportional to the size of ship lifted, unlike graving docks and require less power than shiplifts.

Floating docks are capable of long life and many C&S docks built in the early 1900’s are still in use today. With today’s modern coatings and treatments there is no reason why even longer life cannot be achieved by modern docks.

The modern floating dock can range from a basic shore dependent dock to a sophisticated fully self sufficient floating dock as a complete self contained ship repair facility. Both can be provided as turnkey packages. The type of facilities that can be provided on a dock are:

Floating docks of all types and sizes have been in existence for many years, thus giving the owner the confidence of proven reliability and experience for all sizes of lift.