User Supplied Equipment
On this page: Scientific Equipment Interfaces | Spares | T-handles | Weight and Buoyancy
Scientific Equipment Interfaces
ROV Jason can accommodate wide variety of user-supplied equipment.
All science gear connections (and pressure certification where necessary) must be worked out during the pre-cruise process.
Please contact: jason-precruise@whoi.edu
Pressure Housings
All instruments or other water-tight housings taken to depth are considered potential implodable volumes, and as such must be certified for use on Jason. Implodable volumes are any pressure housing with a non-compensated compressible internal gas volume at a pressure that is either above or below the external ambient sea pressure with a potential to burst or collapse.
Implodable volumes should be pressure tested to 1.2 x the planned operating depth. Each test requires a minimum of 10 pressure cycles as follows: 9 cycles held at maximum pressure for 10 minutes, followed by a single cycle held at maximum pressure for 1 hour. If a pressure vessel was tested by its manufacturer to an alternate specification, that documentation should be sent to Jason OPS for review and could be deemed sufficient.
After any required pressure testing, send certifications to jason-precruise@whoi.edu and bring paper copies with you to sea.
Jason
| Digital: | Minimum four RS-232 (up to 115kbaud). One Ethernet (10/100). |
| Power: | Multiple 24 and one 240Vdc switched circuits. |
| Video: | One composite analog. |
** Potentially able to accommodate other digital/video/power formats and/or quantities.
Medea
| Digital: | Multiple RS-232 (up to 115kbaud). One Ethernet (10/100) |
| Power: | Multiple 24 and one 240Vdc switched circuits. |
| Video: | One composite analog. |
Spares
Many user-supplied sampling devices, cameras and sensors are unique, are likely very specialized, and as such may have a higher incidence of problems during a dive series. The Jason Group strongly recommends that when a science program includes a user-supplied, specialized tool, camera, or sampling device, that sufficient practical spares are available for use in the event of a problem. Examples include spare cabling, o-rings and/or seals, tubing and fittings, valves, power supplies, data interfaces (Moxas) and other critical items that may experience problems or failure during a series.
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A general rule of thumb is to expect some form of minor equipment issue, and to arrive prepared to respond to the problem with a reasonable complement of sparing and tools.
The Jason Group will provide as much expertise and problem evaluation as possible, and where possible and practical, the Group may be able to provide basic equipment support. But for unique sampling devices it is imperative that critical spares are available.
Additionally, the Group recommends that cruise participants bring sufficient ‘dummy’ plugs and caps, capable of protecting sensitive electronic connectors and plugs at depth.
Users should also ensure that they are well equipped with any specialized or unique tools and hardware that are important for the preparation, mounting or support of their equipment.
The Jason Group can provide guidance for spares and tooling as part of the pre-cruise planning process.
T-handles
The jaws of both manipulators are functionally equivalent and consist of opposing overlapping finger pairs. They are specifically designed to grip instruments which are fitted with a standard “T”-handle. The user should align the “T” with the vertical load. The user is cautioned not to assume compatibility between your tools and Jasons manipulators, even if the tools are fitted with T-handles. It is best to seek the advice of the Jason Group on instruments which have not been previously used with the manipulators, regardless of how dependable they may seem. Many biologically and geologically oriented tools, including a variety of pry bars and other rock breaking tools, soft and hard sediment corers, box corers, and current meters have been adapted for use in conjunction with the manipulator jaws and the associated actuator mechanism.
Weight and Buoyancy
The Jason Group calculates the ROV’s payload as a part of the preparation for every dive. Air and water weights of installed user-supplied equipment and sampling tools are included in these calculations. It is important that accurate air and water (buoyancy) measurements are obtained for all science-supplied items intended for use on Jason and/or deployed platforms (elevators). The Jason Expedition Leader will request these weights for all science gear at the beginning of each cruise.
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Although use of a model to calculate air weight and net buoyancy of an assembly is possible, it is much more accurate to obtain air and water weights via empirical means. Air weights may be found via standard means (appropriately sized scale). Buoyancy measurements require that the item be submerged in sea water while measuring the resulting buoyancy. Although not typical, users should be aware that some items may be neutrally or positively buoyant in sea water which could have an impact on use during sampling. These items may be prone to float from the basket and thus require additional consideration.
Obtain weight and buoyancy for fully assembled components where possible and fully submerge the items during measurements. To ensure accuracy during measurements, it is important to ensure all equipment air voids and cavities are fully flooded to the extent possible. For larger items, obtaining buoyancy may require the use of a crane and load cell to fully submerge the item in sea water. With prior planning assistance may be available as a part of cruise mobilization (typically the two days prior to departure from port).
The Jason Group can provide additional guidance and assistance as required.
The National Deep Submergence Facility is sponsored by the National Science Foundation, the Office of Naval Research, and the National Oceanic and Atmospheric Administration.