Umat – Subsea Mattress System

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The Umat Subsea Mattresses are available for hire or alternatively purchase in the case of permanent installation. The system includes several types of subsea mattresses, each developed to include functionality, features and capacities suitable for specific applications and seabed conditions (See system overview).

Support capacity is maximized by low weight, high strength material, high overall stiffness, stiffness in two directions / horizontal plane where applicable, and minimization of gaps and openings within the assembly / between mattress segments. Application and particulars are:

  • Landing support, temporary support, permanent support, heavy-duty support, extreme-duty support, separation, dredged area cover, blanket, ingress protection, rock dump support.
  • Permit use on soft seabed.
  • Deployed without use of lift spreaders (beams or frames).
  • Several types permit ROV positioning on the seabed.
  • Available in various sizes, and several types can be connected together as hinged segments.
  • Deployed as one length, flat pack or in ROV basket, single or multiple.
  • Several optional configurations and features are available for all Umat mattress types.
  • Optional high friction fabric surface.
  • Optional mud skirt for seabed penetration and stabilization.
  • Optional stiffeners between segments (PS & HD Umat).
  • Can be adopted, modified, configured to suit any specified requirements and/or application.
Subsea Mattress System

Umat-Temporary Seabed Support Mattress/ TS Umat

(Rental)

Lightweight high load capacity, soft or hard seabed, temporary support mattress for flowline and umbilical termination heads, connectors, PLR’s, UTA, SUTA, tooling, diver operations, dredgers, and other seabed landed equipment (the most commonly used Umat mattress). It permit ROV positioning / re-positioning on the seabed.

Installed without the use of dedicated lift spreader. Deployment / recovery rigging is included in the rental rate.

Available as single mattress or as a hinged mattress assembly with up to 5 interconnected mattresses.

Typical dimensions (W x L x H) and weights are: 3.60m x 2.0m x 0.08m / 70 kg dry & 50 kg in seawater (1 segment mattress) & 3.6m x 10.2m x 0.08m / 358 kg dry & 268 kg in seawater (5 segment mattress)

Other, widths lengths, and mattresses with or without additional longitudinal or transverse stiffeners are available on request

Datasheet includes dimensional details, weights, illustrations, description of features, configuration details and options.

Subsea Mattress System

Umat-Permanent Seabed Support Mattress / PS Umat

(Rental / Optional Purchase for permanent installation)

Lightweight high load capacity permanent, long term, soft or hard seabed, support mattress for PLEM’s, PLET’s, PLR’s, UTA, SUTA, spool pipes, jumpers, and other seabed placed permanent equipment (can also be used for temporary services). It does not include parts that can corrode. It permit ROV positioning / re-positioning on the seabed.

Includes integrated webbing slings, and is deployed without the use of a lift spreader. Deployment / recovery rigging is included in the rental rate.

Available as 1, 2, 3, 4 or 5 segment mattress.

Typical dimensions (W x L x H) and weights are: 3.8m x 1.4m x 0.05m / 97 kg dry & 27 kg in seawater (1 segment mattress) & 3.8m x 6.6m x 0.05m / 469 kg dry & 134 kg in seawater (5 segment mattress)

The standard width of the mattress is either 3.8m. However, with a width of 1.9m the mattress can be used as a seabed corridor mattress for sea lines.

Other widths, lengths, and configurations are available on request.

Datasheet includes dimensional details, weights, illustrations, description of features, configuration details and options.

Subsea Mattress System

Umat-Heavy Duty Seabed Support Mattress / HD Umat

(Rental / Optional Purchase for permanent installation)

Lightweight very high load capacity temporary or permanent support mattress for soft or hard seabed. Primarily intended for supporting very heavy equipment with a small footprint (E.g. DMA’s). However, can also be used as a Heavy Duty version of the Umat-Permanent Seabed Support Mattress (i.e. 12mm thicker segments). It does not include parts that can corrode. It permit ROV positioning / re-positioning on the seabed.

Includes integrated webbing slings, and is deployed without the use of a lift spreader. Deployment / recovery rigging is included in the rental rate.

Available as 1, 2, 3, 4 or 5 segment mattress.

Typical dimensions (W x L x H) and weights are: 3.8m x 1.4m x 0.06m / 118 kg dry & 33 kg in seawater (1 segment mattress) & 3.8m x 6.6m x 0.06m / 535 kg dry & 167 kg in seawater (5 segment mattress)

Other widths, lengths, and configurations are available on request.

Datasheet includes dimensional details, weights, illustrations, description of features, configuration details and options.

Subsea Mattress System

Umat-Extreme Duty Seabed Support Mattress / ED Umat

(Rental only)

Very high load capacity temporary support mattress for soft or hard seabed. Primarily intended for very heavy equipment with a large footprint and/or an assembly that provides limited seabed support (e.g. subsea winch package, long subsea basket and similar).

Includes integrated webbing slings, and is deployed without the use of a lift spreader. Standard mattress includes 20 off square hollow section steel, SHS profiles, equally spaced at 277mm along the mat length. Up to 18 off additional SHS profiles can be included. Dimensions are 5.5m x 3.2m x 0.07m (L x W x H) / 540 dry – 472 kg in seawater.

Other widths, lengths, and configurations are available on request.

Datasheet includes dimensional details, weights, illustrations, description of features, configuration details and options.

Subsea Mattress System

Umat-Seabed Blanket / SB Umat

(Rental / Optional Purchase for permanent installation)

Tear and wear resistant high strength blanket for subsea / seabed use. Used to cover areas with soft seabed, mud and silt. It will also provide support and prevent sink in of rock dump or similar placed on the seabed. It can also be used to cover subsea equipment and structures to eliminate potential snag points, or to collect / prevent ingress of debris, sand, mud, drill cutting, or other on subsea equipment parts / assemblies. It will protect structures and items from wear and erosion resulting from current and sand flow along the seabed (e.g. ropes in concrete mattresses).

The SB Umat includes 4 off Ufists for ROV positioning / re-positioning on the seabed.

Available as small or large blanket (standard). Dimensions are 3.6m x 2.0m x 0.02m & 5.1m x 3.2m x 0.02m (W x L x H). Multiple blankets can be combined in order to make a larger / longer blanket.

Blanket weight and seabed unfolding is accommodated by 20mm wire located in pockets included along all four sides of the blanket. If requested additional longitudinal or transverse wires can be incorporated into the blanket for weight / positioning purposes.

Other widths, lengths, and configurations is available on request.

Datasheet includes dimensional details, weights, illustrations, description of features, configuration details and options.

Subsea Mattress System

Umat-Subsea Instrument & Small Items Seabed Support Mattress / SI Umat

(Rental / Optional Purchase for permanent installation)

Lightweight very high load capacity and stiff temporary (or permanent) support mattress for soft or hard seabed. Primarily intended to provide seabed support for subsea instruments including tripods or other smaller items, DMA’s or structures that have limited footprint. It does not include parts that can corrode.

Dimensions and weights are 1.9m x 1.4m x 0.06m (L x W x H) / 59kg dry – 17 kg in seawater

Includes integrated webbing strap loops in each corner for lifting and handling, including ROV positioning. Using a pennant wire arrangement, it can be deployed together with the equipment it is intended to support.

Other widths, lengths, and configurations are available on request. It can also be delivered with transponder buckets or other instrument parking interfaces integrated into the mattress.

Datasheet includes dimensional details, weights, illustrations, description of features, configuration details and options.

Subsea Mattress System

Umat Deployment and Recovery Rigging (included and optional)

TS Umat, PS Umat and HD Umat includes deployment and recovery rigging + Ufists for ROV positioning and repositioning on the seabed.

This typically includes:

  • 5 off Ufist, (4 off large on mattress, 1 off small on link), 1 off Master Link, 2 off 3/6m -1t soft sling.

As an option the following rigging can also be provided:

  • Pennant wire, 8 m, with ROV hook in one end, a master link in the other end.
  • Ballast Sling Assembly for deployment (1 off webbing sling, 1 off Ubag, 2 off shackles and 1 off release link).
  • Ballast weights, Ubags, permanently attached to the TS, PS or HD Umat.
  • Flat pack rigging for deployment of multi segment mattresses (can also be deployed with the ballast sling assembly or as unfolded without any ballast).

Additional rigging that may be relevant is subsea Ufloat buoy with 10kg buoyancy in order to prevent the master link from sinking into the seabed when it is laid down on very soft seabed. This arrangement also include two weight sleeves placed onto each of the soft sling legs such that sling assembly does not float up.

All lifting equipment is delivered with certificates.