Transfer Under Pressure (TUP) Diving System

We are offering for sale a Transfer Under Pressure (TUP) Diving System.
The TUP Diving System is a Closed Bell Diving System, designed and manufactured by SMP Ltd.

It is certified in accordance with International Maritime Contractors Association (IMCA) guidelines and codes of practice for offshore diving operations and certified by Lloyds Register of Shipping.

This compact modular system consists of a 3 man 4.7m3 saturation diving bell, diver’s gas control panels (air/mixed gas), main Bell/Diver control panel, twin lock decompression chamber, single lock decompression chamber (optional), HP and LP compressors, gantry launch and recovery system.

The system is equipped for air diving and mixed gas diving and the clump weight also incorporates a tool basket for the divers. A hyperbaric floataway chamber is optional.

The Diving System is a mobile and modular system that can be mobilised on a DPII support vessel, platform, rig or construction barge. The system is designed for moonpool or over the side operations. Using Trimix or Nitrox gas mixtures will allow longer duration in-water bottom time at greater depths than using air diving techniques which cause longer in-water and decompression practices.

By providing a closed bell system the divers are transferred in a protected environment. Safety is increased by removing the threat of Nitrogen intoxication. This is achieved by making sure at no point is the diver exposed to atmospheric pressure during decompression.

The benefits are clear to see and it is the way forward in today’s demanding market for deep air diving operations and continual surface mixed gas operations.

Safe No surface decompression interval, protected transfer to and from the splashzone
Proven An enhanced proven solution that increases workable bottom time
Future Proof Upgradeable to Saturation Diving Capability (Future Proof Capability)
Cost Effective The system provides cost effectiveness through increased bottom times for the divers
Mobile This modular system can be easily transported and mobilised in 24 hours providing fast turnaround for offshore operations on any suitable vessel

There is also the capability for one dive team to be in decompression whilst a second dive team commence diving operations which means less down time on jobs.

Download our Full Product Brochure for all specifications and features

Contact us with any questions or if you are interested in a quotation.

Ask our Team
SMP design, manufacture and supply a wide range of commercial diving equipment, please email or telephone +44 (0)1772 687775 for a quotation on all your commercial diving needs from branded products to bespoke manufactured items all at competitive prices.

Commercial Diving Transfer Under Pressure (TUP) System

SMP’s well established manufacturing and design teams have recognised the requirement of the next step to extended bottom times with air, nitrox and mixed gas diving with the ever increasing demands in the renewable, oil and gas sectors in the offshore industry.

SMP have developed a solution for a closed Bell TUP System which will be a unique one-off design available to interested parties. This system is configurable to client requirements on a short lead time.

Transfer Under Pressure System

The system provides a cost effective diving solution through increased bottom times for the diving teams. This provides the capability for the diving team to be working from a Schedule 6 type Bell whilst the second team will be in decompression after completing their bell diving operations.

This will mean continual productivity from the diving bell teams with less down time and smaller diving crews that would be utilised with normal air and nitrox diving.

Transfer Under Pressure System

The system utilises a minimum 4.5 m3 saturation diving bell which has the capability of bounce diving operations. This is critical to the utilisation of this system. The diving bell can be lowered to the seabed under atmospheric conditions. When the divers arrive at the work site the supervisors will have the capability to pressurise the diving bell equivalent to the work site depth which will allow the divers to exit the bell to proceed with their tasks. This can be a single diver or two diver lock out with a standby diver remaining in the bell.

Transfer Under Pressure System

On completion of the dive the divers will return to the diving bell where the doors will be sealed. At this stage the divers in the bell will start their decompression procedure. The bell will then be recovered to the surface with the divers continuing their decompression within this controlled atmosphere. The bell will be recovered by the handling system into the bell capture arrangement thereafter manipulated onto the bell handling trolley for mating to the divers transfer lock.

The above process allows for much greater productivity with diver’s bottom times, a more controlled and safer working environment and quicker and safer decompression procedures as opposed to the regularly used oxygen surface decompression procedure.

Transfer Under Pressure System

TUP System – Features and Specifications


  • L : 40’ (12 mtr) x W: 11.8’ (3.5 mtr) x D: 11.8’ (3.5 mtr)
  • Weight: 38,000 kgs
  • 2 x Personnel Doors
  • 2 x Heating and Air Conditioning Units
  • 4 x Gas and Air Penetrator Plates
  • 1 x Electrical Penetrator Plates

DDC and TUP:

  • Side Mating Manway and End Mating to SDC (Bell)
  • Divers Transfer Lock with toilet and shower facility
  • 1.8 mtr Twin Lock Chamber for Diver’s Decompression Treatment
  • Built in Master Control Panels
  • Capacity for 8 persons in the Twin Lock Chamber and 3 persons in the DTL
  • System currently rated to 50 mtr SWD but can be re-rated to 18 Bar 180 mtr (590 fsw)
  • Medical Locks and Chamber and DTL
  • Chamber and DTL outfitted with Comms, Lighting, Gas Analysis, CCTV Systems, Cooling/Heating, Scrubbers

Other Equipment:

  • LP Air Storage System
  • Fire Suppression System
  • Electrical Breaker System
  • Distribution Panel
  • Transformers and Battery Back Up Supply

For more information on the TUP system please use the links below:

Our Sales Team and Technical Advisors from our UK office are available to offer help on any questions relating to this system. Please call +44 (0)1772 687775 Mon – Fri (9am – 5pm). Alternatively email and we will get back to you.