Large-format, highly stressed one-off structures up to 50 t – welded, straightened and handed over stress-relieved. As a certified welding contractor to DIN EN 1090-2 EXC3 with heavy-load handling in Lorch (Ostalbkreis · Stuttgart region).
2×25 t crane system in tandem lift – turning and positioning even with an unfavourable centre of gravity.
Fully automated ESAB systems for deep, high-strength seams on large-format structures.
Flame straightening and vibratory stress relieving directly after welding – no furnace size limit, no external logistics.
Portal milling up to 26,000 mm and vertical turning up to Ø 4,800 mm – without splitting the structure.
The highest execution class for load-bearing structures, including weld verification and documentation.
Over 50 crane installations, including 37 wall-mounted jib cranes, plus heavy-duty forklifts up to 16 t.
Heavy welded structures at Bock are large-format, load-bearing steel components – from solid single-piece structures to complex welded assemblies with demanding requirements for dimensions, weight and geometric accuracy.
Unlike welded assemblies, the focus is not on the number of individual parts but on structural size, component weight and handling effort. Normative requirements, close tolerances at large dimensions and high-strength materials define the component profile.
Production is carried out to customer drawings or specifications. CNC machining, shot blasting, painting and assembly operations can be integrated into the project workflow as required.
Fully automatic submerged arc welding where the weld volume becomes too large for manual processes – ESAB masts with up to 7 m outreach.
The crane system turns the structure between passes instead of welding it in a constrained position – weld quality comes from the position.
Flame straightening and vibratory stress relief follow immediately after the weld – in the same plant, with no transport to third parties.
The production facility is equipped with a 2×25 t crane system providing a total lifting capacity of 50 t. This allows large-format welded structures to be handled, turned and positioned safely – even with awkward dimensions or unfavourable centres of gravity.
This crane capacity is a structural prerequisite for components that cannot be moved or fabricated in standard workshops. It is not an optional feature but an integral part of the production infrastructure.
What matters is not just the lifting itself, but turning the component during welding: a structure that can be welded in the flat position achieves better weld quality than in constrained positions. The crane equipment therefore directly determines what weld quality is achievable on a heavy component at all.
Over 50 crane installations in the plant – bridge cranes up to 50 t in tandem lift, 37 wall-mounted jib cranes at the workstations and heavy-duty forklifts up to 16 t move heavy components safely through the entire production.
Depending on component geometry, material and seam requirements, Bock applies different welding processes:
Process selection is based on the requirements of the component. Where necessary, multiple welding processes may be combined within a single structure.
Bock uses predominantly European quality steels with traceable origin. Materials are selected according to drawing and requirements:
The higher the strength and plate thickness, the more strongly the heat input affects dimensional accuracy and residual stress. That is why, on heavy structures, the choice of material is decided together with the post-treatment step rather than in isolation.
Bock Maschinenbau is a certified welding contractor to DIN EN 1090-2 EXC3 and EN ISO 3834-2. Complemented by a certified quality management system to DIN EN ISO 9001:2015, these standards form a binding quality framework for the fabrication of welded structures: welding process qualifications, inspection requirements and documentation obligations are an integral part of production. Current certificates are available as PDF for clients with verification requirements.
For heavy structures the inspection focus lies differently than for multi-part assemblies: what is critical is not the number of joints but the weld cross-section. Deep submerged-arc welds in thick plate cannot be assessed from the surface alone, which is why, at the corresponding weld quality class, ultrasonic testing by our cooperation partner is added in-house – complementing visual, liquid penetrant and magnetic particle testing with Level 2 qualification of our own inspectors to DIN EN ISO 9712. Scope and documentation are defined per component according to drawing and normative requirements.
This covers surface indications, cracks, near-surface irregularities and internal irregularities in suitable components and weld joints.
Inspection and documentation requirements are agreed on a project basis according to drawing, normative requirements and customer specifications – ensuring that quality assurance is tailored to the individual structure rather than applied as a blanket measure.
Certified welding contractor for load-bearing steel structures – qualified up to Execution Class EXC3.
DVS ZERT · Zertifizierungsstelle des DVS download as PDFComprehensive quality requirements for fusion welding of metallic materials.
DVS ZERT · Zertifizierungsstelle des DVS download as PDFCertified quality management system – full process traceability and audit-ready documentation.
TÜO · Technische Überwachungsorganisation für Sicherheit, Qualität und Umweltschutz GmbH download as PDF1 / 3
Welded, tested and fully machined — with no stop in between.
Heavy welded structures frequently require further production steps. The following operations can be integrated into the project workflow as required:
Heavy welded structures can therefore be not only welded but also machined, surface-prepared, coated or pre-assembled within the same production facility – subject to agreement and project requirements.
Heavy welded structures from Bock are produced for technically demanding applications where dimensions, weight and certification are critical:
If, on the other hand, the size of the individual component is not the focus, but rather the number of joints and dimensional accuracy across many connections, the production of welded assemblies provides the appropriate framework.
Bock Maschinenbau has been producing heavy welded structures at its Lorch site for over six decades:
Crane, plant and special-machine builders from the Stuttgart area and the DACH region source load-bearing heavy-duty welded structures up to 50 t from our EXC3 facility in Lorch.
With heavy welded structures, the focus is on structural size, component weight and handling effort; with welded assemblies, it is on the number of joints and dimensional accuracy across many connections. Accordingly, what counts on heavy structures is less the number of welds than their length and cross-section – long longitudinal seams in the SAW process, connections and repairs by hand.
Yes. A 2×25 t crane system with 50 t total lifting capacity turns the structure between passes, so that welding is done in the flat position instead of a constrained position – even with unwieldy dimensions or unfavourable centres of gravity. For transport through production, over 50 crane installations, including 37 jib cranes, and heavy-duty forklifts up to 16 t are available.
By flame straightening and vibration stress relief, which follow immediately after welding in the same plant. Flame straightening corrects welding distortion thermally without material removal and without size limitation from furnaces or fixtures; vibration stress relief (VSR) reduces residual stresses without heat, even on structures that do not fit into any annealing furnace.
Not as long as it fits into the working envelopes: portal milling up to 26 m travel and vertical turning up to Ø 4,800 mm turning diameter and 25 t table load allow the structure to be finish-machined in one piece.
Send us your drawing, material, plate thickness, largest dimension and inspection requirements. We weld, straighten, stress-relieve and machine the structure at the same site – or take on the welding only.
