Ship demolition – often also referred to as ship recycling or ship dismantling – is a multifaceted process of disassembly, separation, and sorting of materials. The focus is on safe workflows, environmentally compatible handling of hazardous substances, and efficient dismantling of hull, superstructures, and equipment. In addition to steel and composite structures, components made of concrete or cementitious grouts frequently occur, for example at machinery foundations, cable penetrations, or ballast. Depending on the situation, concrete demolition shears or stone and concrete splitters can contribute effectively, while steel and combination shears, Multi Cutters, and tank cutters are considered for hull sections and tanks. The equipment is typically supplied by hydraulic power packs and must be suitable for confined spaces on board as well as dock- and shoreside situations.
Definition: What is meant by ship demolition
Ship demolition is the planned, safe, and as low-emission as possible dismantling of an end-of-life vessel into its components to recover valuable materials and properly remove hazardous substances. The work typically takes place in dry docks, at piers, or at specialized shipbreaking yards. The process includes emptying and cleaning tanks, selective removal of equipment, cutting hull sections, and the single-grade separation of metals, plastics, wood, and mineral construction materials. Depending on the design and condition, thermal procedures or cold separation techniques are employed, such as hydraulic shears, tank cutters, Multi Cutters, and—for mineral components—concrete demolition shears or stone and concrete splitters.
Process of ship demolition: from arrival to dismantling
A professional ship demolition follows a clear sequence: first come document checks and hazard assessment; the vessel is then brought into a safe position (e.g., blocking in the dock), residual media are removed, and tanks are inerted and cleaned. Next, selective removal of equipment and interior fittings begins, followed by the structural segmentation of the hull into manageable sections that are further processed by single-grade separation. While steel and composite parts are largely separated by cutting and shearing, grouted machinery foundations or cementitious toppings often require mechanical breaking or controlled splitting. At every step, emissions (sparks, noise, vibration), exposures affecting personnel and the environment, and restricted onboard access must be taken into account.
Methods and separation techniques compared
Cold cutting with hydraulic shears
Hydraulic steel shears, combination shears, and Multi Cutters separate plates, sections, girders, pipes, and cables without flame. This is advantageous in sensitive areas with residual gases or in confined spaces, as it minimizes sparks and heat input. Tank cutters are designed to open and portion tanks and tank sections, provided they have been safely cleaned and declared gas-free in advance.
Thermal cutting
Oxy-fuel or plasma cutting is efficient for large plate thicknesses and long separation cuts. Where hot cutting is inadvisable due to fire or explosion hazards, a combination of pre-drilling, scoring, cold cutting, and controlled lifting-off of segments can be the safe alternative.
Selective deconstruction of mineral components
Where concrete, mortar, or grouts are present—such as at machinery foundations, flame-retardant cable penetrations, locally cast plinths, or ballasted areas—concrete demolition shears are suitable for targeted removal, while stone and concrete splitters enable low-vibration, explosive-free separations. These methods reduce vibration transmission to adjacent structures and are suitable for work in dock facilities, at quay edges, or in the immediate vicinity of sensitive equipment.
Relevant tool categories and typical applications
- Steel shears: Section-by-section dismantling of hull plates, frames, stringers, and structural sections; reduction to transportable sizes.
- Combination shears: Switching between cutting and crushing, useful for mixed constructions or tight access.
- Multi Cutters: Cutting pipelines, cable trays, thin-walled sections, and attachments as part of the strip-out.
- Tank cutters: Opening, trimming, and portioning tank areas and vessels after gas-free clearance and cleaning.
- Concrete demolition shears: Removing concrete grouts, exposing embedded fittings, and removing localized foundations on decks or in engine rooms.
- Stone and concrete splitters / stone splitting cylinders: Low-vibration separation of massive concrete elements, e.g., at dock structures, quay blocks, or heavy ballast bodies.
- Hydraulic power packs: Power supply for tools on board, on the pier, or in the dock; modularly adaptable to different power demands.
Application areas in the context of ship demolition
- Concrete demolition and special dismantling: Selective removal of foundations, grouted areas, and quayside concrete components; use of concrete demolition shears and stone and concrete splitters for controlled removal.
- Strip-out and cutting: Step-by-step clearing of interior areas; cutting pipelines, cables, secondary steel, and attachments with Multi Cutters, combination shears, and steel shears.
- Rock demolition and tunnel construction: Interfaces arise in port and dock environments, for example when adapting slipways or dock areas in rock; splitting methods are relevant as complementary techniques here.
- Natural stone extraction: Rare directly within ship demolition, but relevant during harbor alterations when natural stone walls or block constructions must be removed.
- Special operations: Work under confined, emission-sensitive, or vibration-sensitive conditions; cold, hydraulic methods and low-vibration splitting techniques are prioritized.
Safety, environmental, and health protection
Protecting personnel, the environment, and infrastructure is paramount in ship demolition. This includes safe gas-free testing and cleaning of tanks, controlled handling of potentially hazardous residues, minimizing sparks, noise, and vibration, as well as effective dust extraction. Requirements can vary by location; binding provisions must always be taken from the applicable regulations and authority specifications. Hydraulically driven shears, concrete demolition shears, and stone and concrete splitters support a cool, controlled separation and help reduce ignition sources—especially in confined spaces and where residual media are present.
Material flows, recycling, and single-grade separation
The quality of ship recycling is measured by the degree of single-grade separation. After the strip-out, steel fractions, non-ferrous metals, plastics, wood, and mineral materials are separated and routed to recovery. For concrete and mortar areas, exposing embedded components with concrete demolition shears is recommended, followed by controlled breaking or splitting to recover reinforcement in a single-grade manner. Seamless documentation of material flows facilitates traceability and quality assurance.
Particularities of concrete and composite components on board and in the dock
Even though the ship’s hull is predominantly steel, mineral materials appear in several locations: grouted machinery foundations, cast concrete cable or pipe penetrations, local ballast, and cast plinths in deckhouses. In addition, massive concrete components are common in dock and pier areas. Concrete demolition shears enable precise removal of such areas without unnecessarily loading adjacent structures. Where vibration and noise must be minimized—such as at quay edges or in densely built harbor areas—stone and concrete splitters provide a controlled, explosive-free alternative to segment massive bodies into transportable pieces.
Work in confined spaces and limited areas
Ship demolition often means working in shafts, bilges, double bottoms, and tank spaces with limited access. Compact, hydraulic tools that can be supplied via hoses from a safe area support occupational safety here. Multi Cutters and combination shears show their strengths when cutting pipelines and secondary steel; concrete demolition shears are helpful when grouted inserts must be exposed without overloading the surroundings.
Planning, logistics, and energy supply for the tools
A coherent supply concept with hydraulic power packs, hose management, and sufficient reserve capacity is crucial for stable operations. This allows parallel work—such as strip-out, steel separation, and concrete removal—to be coordinated. Short routes, defined handover points, and clear labeling of fractions reduce downtime and increase process reliability.
Quality criteria for clean separation cuts and reliable processes
- Appropriate method: Hot or cold cutting depending on risk situation, material thickness, and work environment.
- Stable handling: Safe positioning and support, ergonomic tool guidance, and sufficient working space.
- Emission control: Reduction of sparks, dust, and noise; needs-based extraction and shielding.
- Single-grade separation: Consistent exposure and separate routing of materials, especially for composite and built-in components.
- Documentation: Traceable recording of steps, approvals, and material flows.
Role of Darda GmbH in the context of ship demolition
Darda GmbH specializes in hydraulic separation and demolition technology. In the context of ship demolition, concrete demolition shears and stone and concrete splitters are particularly relevant for mineral components, while steel shears, combination shears, Multi Cutters, and tank cutters can be used for the cold separation of metallic structures. Hydraulic power packs from Darda GmbH provide the necessary energy supply. The selection of suitable tools is always based on the material, accessibility, and requirements for safety and emission reduction.