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.

Case Study: Crowley:Titan Salvage / SMP – Containerised Dive System

SMP have been working alongside Titan Salvage to design and manufacture a Containerised Dive System for use on a salvage project in South Africa. Read our case study about how the project developed.

About Crowley Maritime Corp: Titan Salvage

Crowley Maritime Corp. subsidiary Titan Salvage is a world leader in the provision of salvage, wreck removal and maritime emergency response solutions, providing world-class services that ensure long-term company durability while ensuring the safety of their people, the public, and the environment.

Titan Salvage along with the Italian underwater construction firm Micoperi received worldwide publicity in May 2012 when they were awarded the salvage contracts for the Costa Concordia cruise liner which famously sank off the coast of Isola del Giglio in Italy on 13 January 2012.  The expected cost of their salvaging plan, which came to more than US$300 million, makes it the most expensive salvage operation ever.

Sub Marine Manufacturing & Products Ltd (SMP) has previously provided bespoke engineered solutions to Titan Salvage on a number of occasions in support of their pursuit for excellence in offshore commercial diving operations.

The Challenge
Titan Salvage approached SMP in early 2014 to purchase a new standard of containerised dive system which would be designed to the individual and exacting requirements of Titan Salvage for use on a salvage project in South Africa.  Specifically they were looking for a hybrid container design that would support both Dive Control operations combined with supporting breathing air machinery all within a single 20ft ISO shipping container.

Within the container designs were several considerations which would need to be incorporated as follows:

  • Environmental control to support use in hot weather climates
  • Dual electrical voltage supply (USA and UK)
  • Integrated LP/HP breathing air compressors together with LP/HP air storage
  • 3 Diver gas control panel
  • Diver CCTV monitoring and communications

Due to the bespoke nature of Titans requirements, an initial design drawing was going to be required to see how we would squeeze all of the required equipment into a single 20ft container.

The Solution – Initial Consultation and Design Proposal
Following a meeting with the client here at SMP to better understand the requirements of Titan Salvage, the SMP in-house design team set to work and produced a series of detailed general arrangement drawings which were then agreed with the client.

The images shown below are a selection of the general arrangement proposal drawings which were sent to the client for approval following our meeting to understand in detail their requirements.

Following approval from the client of the general arrangement drawings we then proceeded to full manufacture.  During the manufacturing process SMP worked closely with the client  who was regularly onsite to monitor the progress of the build and to provide any feedback.

Dive Control area with 3 Diver Gas Control Panel with Gas Analysis, diver comms and diver CCTV monitoring station.

8 x 50Litre Cylinders HP Gas Storage Bank, Decant Panel and Coltri MCH 36 Breathing Air Compressor.

Louvered Container Panels Were Used Along with Air Conditioning to help with the environmental control

Bulkhead wall with PVC windows and door along with solid wood worktops

LP Air Compressor, Receiver and Additional Vertical Air Receiver

The Result
This date critical system was completed and delivered on time, in full and on budget for use on a salvage project in South Africa to the clients’ complete satisfaction.  The client Titan Salvage are very happy with the system and are now proceeding to upgrade their other containers to this same high standard of specification and quality.

Daniel Dolson who is the Operations Manager for Titan Salvage worked closely with SMP on this project and provided the following feedback:

“Titan Salvage is proud to take ownership of our newest containerized system built by SMP in the UK. This three diver air system was built to Titan’s specifications, addressing issues such as hot weather climate work, dual electrical voltage (USA and UK), and built-in compressors and safety systems. Thank you to the team at Submarine Manufacturing for putting this system together for us! This is the second unit in a series of three on order. The first two delivered systems are currently working in South Africa on a Titan salvage project. ”

Download this case study (PDF Format)

Saturation Diving Equipment Sale

We are currently offering for sale the component products that together will build a complete 300 metre Saturation Diving System.

By purchasing the full system there will be a significant saving over the price of the individual component items.

Included in the package are: -

SH104847 – Self Propelled (12 man) Hyperbaric Lifeboat (SPHL) & Launch System
SH104845 – 3 Man Diving Bell (4.7m³) rated to 300 metres
SH104841 – 300 metre Twin Lock Sat Chamber (6 man) Main Lock & TUP Entry Lock
SH104842 – 300 metre Single Lock Sat Chamber (4 man)
SH104857 – Bell Handling System with PLC Control Cabin and 300msw Sat Chamber

Please contact us today for prices and delivery options on our Saturation Diving System.
Tel: +44(0)1772 687775 /

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.