Harland and Wolff - Shipbuilding and Engineering Works

 Shotblast and Paint Hall complex at Belfast

A shipyard's ability to construct massive hull sections demands an equivalent ability to protect them from corrosion - rapidly and effectively. This aspect of shipbuilding, the surface preparation and subsequent coating of large complex weldments has been undergoing significant change as modern yards throughout the world move to new methods of construction.
Work-handling methods have assumed new importance in an era of high labour costs; but a more rationalised approach is also needed since stringent specifications now govern the standards of surface preparation and paint application for optimum coating life.
To reach these standards surface protection procedures require that shot blasting and coating - traditionally outdoor operations - be conducted indoors, free from the vagaries of the weather. The paint hall provides for enhanced production performance and to strict blasting and painting standards.

The under-cover painting concept involves the erection of a paint hail as part of the shipyard's production line. Containing two or more paint cells, the hall is designed to handle, in rotation, the surface preparation and Coating of fabricated sections. What is probably the largest and certainly the most advanced example of this concept is the multi-million pound paint hall recently completed in the Belfast shipyard of Harland and Wolff, Limited, for whom Babtie Shaw & Morion of Glasgow acted as the consulting civil and structural engineers.

Although at Harland and Wolff's yard shotblasting and priming have been performed under cover for many years the new facility meets the need for more economic methods of handling and rationalises the Company's whole approach to the surface protection of large weldments. Final painting of the ship is, of course, done outdoors.


Weldments up to 500 tonnes are shotblasted to a predetermined international standard. This is followed by recovery of the spent abrasive and then by the coating and curing processes. The entire operation is carried out in dust-free surroundings in which ambient temperatures and humidity's are controlled in order to meet the requirements of a particular coating. The building of a modern ship - between 60 000 and 500 000tdw - is a production line operation and a brief description of Harland & Wolffs steel facility indicates the scale of operations and the role and purpose of the paint hall.

Steel-working facilities
Steel in standard plates and sections from the unloading quay is stored outside in four main stockyard bays 245m long by 40m wide, provided with cranes of up to 16 tons capacity for plates and 7 tons for sections. Buildings in this area house plant for straightening, shotblasting and priming the plates and sections. Uncut steel, after straightening, is passed on roller conveyors' through a high production automatic airless shotblasting machine to remove mill scale. At this early stage shotblasting poses few of the problems encountered when blasting fabricated steel. Plates and sections are primed automatically. Blasted and primed steel is transported to the plate burning shop for culling and edge preparation and to the section shop for assembly line preparation of sections for fabrication. Transferred to the panel shop for assembly line production plates and sections are formed into stiffened panels of up to 240 tons weight. The plate shop is 150m long and the section and panel shops are each 210m long. Movement of plates is via a small transfer trolley. Sections travel via a transverse co-ordinator.

 

It is in the vast build-up shop, 180m long and 55m wide with a height to eaves of 355m that ship sections of up to 500 tons in weight are fabricated. Two 200- tonne and two 40-tonne cranes running on rails at different levels cover the whole floor area. Large doors 21m high permit the removal by transporter of the fabricated units to the paint hall.

Paint hall
Here massive ship sections are sited on stools 2 metres high so that every surface can be reached for blasting and coating.
Owing to earlier handling and the welding and fabrication procedures, the weldments on arrival must be blasted to achieve a surface suitable for application of either conventional or modern sophisticated coatings. The average estimated area to be blasted and coated per weldment is 560m , and is normally accomplished by nine blasting operators. However the Harland and Wolff paint cells have provision for operating with up to 13 operators. Abrasive recovery time is reckoned additionally.

 

In practice all weldments are usually blasted and painted in the same cell. This is permissible because of the highly effective means adopted for recovering the spent abrasive and for dust and paint fume extraction, and desirable because heat would be lost and the risk of rain damage to the cleaned surface increased 8 tons of grit per hour per unit. Each integrated Munkebo unit consists of two pumps and two cyclone separator - collectors to remove dust and oversize particles.

Separated steel grit is delivered for re-use via the silos through a vibratory air wash cleaner to storage hoppers, each of which is capable of feeding five blast machines. Suction pick-up hoses and self-propelled cars are employed for initial retrieval.

Heating, ventilation, dust extraction, cleaning and painting
As the primary purpose of dust extraction is to provide optimum operator visibility a high rate of extraction is essential. High efficiency extraction is also required to remove paint fumes. The advanced ventilation and dust separation equipment demanded by the three operations of blasting, painting and curing has been supplied by AB Bahco Ventilation of Enkoping, Sweden. The firm has also supplied the plant through which heated air enters the paint cell at ceiling level and is blown down to floor level. Polluted air is extracted through wall vents close to the floor. After cleaning, by scrubbing, it is vented to the atmosphere.

The Bahco cascade scrubbers installed in the main central corridor operate on the principle of wet separation, using the impact of nigh velocity air on liquid to create intense turbulence and droplet dispersion. The dust-laden air is cleaned by intimate contact with the liquid and the separated dust in the form of a sludge is collected for disposal. Coatings are applied by the airless spray method. Six wall-mounted 47:1 ratio pumps are allocated to each cell.

Additionally, and stored in the annexe, are six portable pumps with paint mix and cleaning equipment.

Services and amenities
The Harland and Wolff paint hall includes suspended work platforms - six electrically-operated platforms per cell with push button control; compressed air system fed by four air compressors with outputs of 64m3/min each al 8kg/cm2; fire protection system - the complete building is monitored by flame smoke arid gas detectors; control room, and an amenity annexe with lockers, showers and rest rooms for a 30-man shift.

Thus grouped under cover are the services and the essential equipment needed for a high standard of surface protection a facility that is rapid, effective and continuously available whatever the external circumstances. The paint hall complex now nearing completion at Harland & Wolff's yard sets the pattern of future developments in progressive shipbuilding yards elsewhere.

 


Since 2007 the Paint Hall has been reinvented as "The Titanic Studios". At 110,000 sq ft it is one of Europe’s largest film studios. Attracting producers such as HBO, Universal and Playtone, the set has welcomed international productions including ‘Game of Thrones’, ‘Your Highness’ and ‘City of Ember’.

Timeline