Marine science researchers have employed submersibles such as the Alvin, the two Johnson Sea-Link submersibles, the Clelia, the Pisces IV and Pisces V as effective platforms for oceanographic observations, collections and experiments for several decades. In the future, the inventory of Human Occupied Vehicles (HOVs) may change but the concerns for safety will remain. The terms “Human Occupied Vehicles” and “Human Occupied Submersibles” are used interchangeably throughout this chapter.
Safety, both for the personnel embarked aboard the HOV and for those aboard the support ship, is paramount in establishing the operating procedures under which Human Occupied Submersibles support science research missions. Over the years, operating institutions have each developed checklists, personnel training syllabi, testing procedures, maintenance intervals, and safety reviews. Conscientious operators have kept pace with advances in material sciences, metallurgy, composites, hydraulic systems, handling systems, electronics, and science tools and have continually improved their systems in relevance and utility for the science users, training of operational personnel, and in overall safety.
An HOV system consists of three major components: the undersea vehicle, the submersible support surface platform, and the handling system that moves the submersible across the air/water interface. Regulatory agencies and experienced operators worldwide focus on the essential synergy of these three elements to provide an effective and safe tool for undersea research and exploration and the personnel supporting this endeavor. Common Certifying agencies in the U.S. are ABS and NAVSEA. Consideration will be given to foreign certification on a case-by-case basis with ultimate authority to accept such certification lying with the home institution.
Regulations based on type and certification of HOV and regulatory status of vessel.
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Any UNOLS vessel or vessel chartered by a UNOLS institution in accordance with Chapter 18 of these standards will adhere to the UNOLS HOV Safety Standards when conducting any operations involving submersibles designed to carry human occupants.
All HOVs must meet all applicable inspection standards and be currently certified by ABS or the U.S. Navy or other such bodies recognized for that purpose within established regulatory compliance regimes.
The surface support vessel must have the ability to conduct two-way communications with the HOV both on the surface and beneath the surface throughout the design-operating envelope of the vehicle in whatever sea state operations are to be conducted. Typically, this will include VHF radiotelephone communications when the HOV is on the surface, and an acoustic underwater telephone system when the vehicle is submerged. A Loss of Communication Procedure must be provided.
The support ship must have a means for electronic tracking of the position and depth of the HOV.
Transducers for acoustic tracking and communications systems, both on the surface ship and on the submersible, must be mounted so that there are no blocked azimuth angles, and so that the propagation covers maximum horizontal distances and depths expected to be encountered under both normal and emergency operational scenarios
Personnel assigned to operation of the tracking/communications equipment on the ship must be provided with proper training, spare parts, and technical support. The importance of training cannot be over-emphasized. Please see HOV Safety Standards Chapter 7.
The surface support ship must have an adequate suite of depth sounding equipment to determine, with precision and certainty, the depth of the water in which the HOV will be operating. Sufficient spares, backup systems and technical support of these essential components must be provided.
Rescue assets and outside assistance for an entrapped or entangled submersible may, depending upon operating area and environmental conditions, be days away. The surface support ship and/or submersible must be equipped with a self-rescue capability. This may consist of a second HOV, a ROV system, a releasable personnel sphere, or a passive buoy tag-line captive engagement system. The self-rescue system must be operational throughout the depth range at which the submersible is capable of operating. Realistic drills and exercises, simulating a submersible rescue scenario shall be held at regular intervals, no less than once a year, and the results must be documented, to assure the integrity of the rescue equipment and to familiarize the personnel on the surface ship and the HOV with its use. These may include tabletop exercises or comprehensive reviews of safety or rescue plans.
In the event of entrapment, entanglement, or component failure, life support for at least 72 hours should be available in the submersible (i.e. air, water and food).
As per maritime law and tradition, the Master retains responsibility for and authority over all operations conducted aboard the ship, including the deployment of any off-board vehicles employed by the vessel and its embarked personnel. The Expedition Leader (or other appropriate official title) is responsible for and has authority over the HOV and its embarked personnel. The designated HOV pilot commands his or her vehicle and has responsibility for and authority over its operation. The Chief Scientist, as described elsewhere in this document, is in charge of the mission. Unless accomplishment of the expedition plan is unsafe or illegal, the Master and other key individuals responsible for HOV operations should make every attempt to facilitate science needs.
Four persons have launch veto authority. The Master, the Expedition Leader, the HOV pilot, or the Chief Scientist can make a “no-go” decision. (On occasion, the HOV pilot may also fill the role of Expedition Leader.) The others may not outvote or over-ride such a call. A decision to proceed with a HOV dive should be a consensus decision of these key leadership personnel, but it must be understood that a majority cannot over-rule a “hold” or “no go” determination by any one of these key personnel.
Similarly, a decision to terminate a dive early and to recover the HOV may become necessary due to a change in the weather, mechanical issues on the HOV or the support ship, conflicting traffic, or personnel needs. Again, any one of the key leadership personnel identified in the preceding paragraph can order an early termination of the dive. The final say on the actual timing of the surfacing (unless there is a situation requiring the submersible to make an emergency ascent) is routinely deferred to the Master who will take into account actual surface conditions and the position of the ship with respect to the HOV, maneuvering the ship as required for the recovery procedure.
Prior to the commencement of HOV launch procedures, the following steps must be taken: (Operators will define step-by-step checklists.)
The institution’s Procedures Manual must address unique operations such as multiple simultaneous HOV operations, simultaneous HOV and ROV or AUV operations, submersible rescue drills, and coordination with other research vessels present in the immediate area.
All UNOLS Ocean Class and Global Class ships operate under ongoing safety management systems as per the International Safety Management (ISM) treaty and national implementing laws and regulations. Smaller vessels in the UNOLS fleet are encouraged to comply with ISM to the fullest extent possible.
ISM Procedures for UNOLS vessels already mandate specific written plans for over-the-side science operations, however these may be fairly generic. Ships conducting launch and recovery of HOVs shall also define specific procedures and include them in their reviewed and approved ISM handbooks and other documentation, as required.
Additional information regarding HOV handling systems is covered in the HOV Safety Standards, Chapter 6.
In general terms, a submersible handling system for the launch and recovery of a HOV is a robust, specially designed piece of precision heavy-lift equipment, built, operated and maintained to exacting standards so that the delicate and human-occupied submersible can be safely and securely hoisted off the deck, placed into the water and recovered after the dive operation--while under full control during the widest possible window of sea-state conditions. The handling system:
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A vessel supporting a human occupied submersible should offer adequate space for routine servicing and maintenance of the embarked HOV. This may include such elements as a machine shop, an electronics shop, or a dedicated space on board for these functions. Separate storage space for the submersible’s spare parts should be provided in a secure location where they will not be depleted to meet other routine ship maintenance needs. Since maintenance and battery charging often take place at night, adequate lighting of the HOV work area should be provided. The lighting should be aimed so as to illuminate the submersible while not blinding the bridge watch-keeping personnel.
The ship should be equipped with a multi-beam seafloor sonar mapping system, which can be used to map the operational area before the HOV is deployed. These systems provide data of considerable utility to the science investigators and also enhance safety and security by verifying the depth and topography of the seafloor, the presence of wrecks or other entanglement hazards, and assist in localization of the submersible and positioning of a rescue vehicle during an emergency.
Equipping the vessel with an acoustic Doppler current measuring system is recommended. This sonar can help the operators determine the presence, direction and velocity of undersea currents, before the HOV is launched, and assist the surface vessel in determining environmental factors critical to dynamic-positioning (see next item.)
Dynamic positioning systems will enhance the ability of the support ship to carryout the HOV mission. These systems serve to efficiently keep the vessel within a defined circle of position over the vehicle’s dive site. Some systems permit automatic tracking of the submerged vehicle’s acoustic transponder, moving the surface ship in concert with the submersible. The bridge personnel can thus better dedicate their attention to monitoring systems and watching out for conflicting surface traffic during lengthy dive operations.
Submersible support from a surface ship is sufficiently unique as to require specialized training for personnel involved in these operations. This training should include the Master, the bridge watch-keeping officers, the sonar/underwater communications and tracking operators, swimmers (if used), deck personnel, and handling system operators. As required for seagoing personnel under ISM, a syllabus for training shall be established and sign-off documents of training milestones and qualifications shall be maintained.
Emergency exercises and drills shall be held to verify the readiness of the rescue and emergency equipment and the personnel tasked with its employment. Pre-dive briefs and post-dive debriefs along with post exercise critiques are useful practices for advising personnel about performance needs and opportunities for improvements. Institutions operating HOVs are encouraged to share experiences through professional organizations, technical journals and publications, submersible operations sessions at professional meetings.