Keel blocks

Malin Abram have a long history of lifting, moving and turning heavy loads and our latest product facilitates just that. Our close relationship with some of the largest ship builders in the UK have enabled us a unique insight into the challenges faced when building some of the heaviest structures in the world, ships. That is when the idea for Malin Abram’s Keel Blocks was developed.

Traditionally keel blocks have been made from timber, steel or concrete often using a mix of multiple materials as packing to create a level platform on which to rest the ships keel. For those less familiar with shipbuilding terminology, the keel of a ship is the main structural longitudinal member running the length of the ship at bottom of the hull. During the ship building and docking process an array of blocks are positioned at various locations below the ships hull. Running along the centre line is an array of keel blocks, sized and arranged to tie in with main structural elements along the length of the keel. The outer curved surface (or bilge) of the ship is supported by bilge blocks like the keel block but typically these are profiled to match the curvature and contours of the ships hull. After all in normal operation on water the hull of the vessel is fully supported by the hydrostatic forces exerted on the hull by the surrounding water. During construction and maintenance the ship would be supported on a combination of keel and bilge blocks.

A detailed view

Design

Completely customisable design ensures blocks can be designed to accurately tie in with vessel transverse frames and vessel specific loadings of approximately 400 Tonnes

height

Height adjustable keel blocks allow for variations in keel profile and dock floor to provide a uniform platform for the vessel keel

finish

Painted in accordance with Norsok System 7B for maximum protection even if submerged for long periods

Extras

Cathodic protection, handling lugs, forklift pockets can all be included as part of the design

Strength

High strength rubber interface between block and vessel ensures maximum protection to vessel surfaces

Adjustable

Removable low profile hydraulic cylinders facilitate quick and manageable adjustment, installation and removal

load monitoring

Load monitoring of the forces in the hydraulic lifting cylinders facilitates removal and reinstallation at previous load levels maintaining even keel loading

speed

Two speed manual hydraulic pump system trolley mounted for speed of installation and storage of cylinders when not in use

Durable

High strength corrosion resistant lead screw and nut materials provides longevity in the harshest of marine environments

We have a track record in designing and delivering bespoke handling solutions to some of the most prestigious clients in the maritime industry including Babcock, BAE Systems and IHC.

One of the many challenges faced by shipyards and ship builders is that during construction and or maintenance, individual keel blocks may need to be removed or repositioned to access a particular section of the keel or hull for inspection or maintenance. The process of keel block removal is not straightforward and once removed repositioning also poses a completely new set of challenges. To tackle this, Malin Abram have developed a removable keel block. Manufactured from high strength steel, the blocks may be designed to meet specific customer requirements, however the fundamental principle remains the same, with each block made of two halves. This is combined with a base, designed to distribute vessel loadings into the dock floor and a top designed to tie in with structural framework and bulkheads for effective load distribution. Connecting these two halves is then a set of adjustable screws, and location points for heavy load hydraulic cylinders. Principally the system is mechanical however adjustment and removal is achieved through the use of heavy lift cylinders. A typical sequence of operation prior to installation would be as follows.

Once each keel block height is set they can be installed within the dry dock prior to docking the vessel. The benefit of an adjustable keel block is that once the vessel is docked each keel block can be inspected to ensure it is making contact with the vessel and is in the correct location. If a particular keel block needs to be adjusted the below procedure can be applied to increase the height of the block and the appropriate load can be applied to ensure load distribution falls within the expected range.
In addition to adjustment, the Malin Abram keel block design facilitates the complete removal of an individual keel block while also providing the ability to record the installation load, so that when reinstalled the load can be reinstated to its pre removal value.
When reinstalling a keel block that has been previously removed, the operator only needs to ensure that the hydraulic cylinders are pressurised/loaded to the pre removal value, prior to tightening the load bearing and locking nuts. This ensures that the previous loading in adjacent keel blocks is also restored, maintaining a more even load distribution within the keel, the keel blocks and the dock floor.

Our capabilities are focused on the needs of the customer and we can tailor our existing product designs to meet specific customer requirements. Our team of highly skilled experienced individuals are able to design in 2D and 3D CAD systems and complete structural analysis using Finite Element Analysis to ensure our products meet exacting customer expectations to the utmost accuracy.