mattm's picture
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How many crew does Endeavour need to successfully carry out her deep-space mission? This is a question being asked throughout the vessel development team, not least because they need to ensure room for everyone to sleep. The question is also critical to the design of vessel systems that will need crew to support them. Automation and AI built into the command and control system significantly reduces the number of crew needed to operate most systems, but there must still be sufficient crew to cope if systems malfunction or are damaged and manual intervention is required.

Endeavour is currently forecast to carry a core crew of 155. Trainees, additional mission specialists and a marine contingent will bring the total crew aboard close to 200. This is comparable to the latest generation of nuclear attack submarines (a core complement of 134 for the US Navy Virginia class), bearing in mind Endeavour will also carry a large team of science specialists.

Watch System

The vessel’s crew is arranged around a watch system which allows the vessel to constantly operate at full capacity. Three teams are maintained, one for each watch, each capable of independently supporting the vessel’s critical systems and cruise operations. During alert conditions, additional senior crew will augment the watch team to provide additional functions such as weapons and damage control.

Discussion is ongoing about the structure of the watch system. The need to have crew alert and at peak performance favours shorter six-hour watches. Another advantage of what is effectively an 18-hour day is that crew naturally rotate through different watch periods during their cruise, meaning they participate in a full range of drills.

Longer 8-hour watches are a better fit for human cycadean rhythms as they ensure a full eight hours of sleep at the same part of the day. However this also means that crew are always on duty in the same watch period – reducing exposure to drills and training opportunities - unless a rotation system is employed (which itself introduces cycadean issues).

Each vessel system required for cruise operations has a team of crew specialists allocated to it for each watch. Each team is supervised by a System Chief – a crew specialist with a rank of petty officer or above. System teams are grouped into a number of functional areas (departments) which are the responsibility of a Watch Officer. Each System Chief reports to the Watch Officer for their area.

Overall responsibility for each watch falls to the Officer of the Deck (OoD), drawn from the pool of senior officers aboard. The OoD is in command of the vessel’s operation and their orders are followed until the Captain or First Officer relieves them and takes the conn. All Watch Officers report to the OoD.

Command Structure

Senior crew including the Captain and Executive Officers operate outside of the watch system, on duty whenever they consider appropriate and not assigned to a particular watch. These positions have overall responsibility for running their departments, including resourcing, maintenance and performance.  

Where a department does not have an executive officer – such as tactical, navigation and operations – the senior officer is appointed department head and assumes overall responsibility. This role is performed in addition to rostered watch duties.

All other officers are assigned as Division Officers, responsible for a crew team (or ‘divisions’) assigned to them. Divisions are unrelated to rostered watches – a crew member can expect to serve with their division for an entire cruise but is likely to serve with different watch officers. Division Officers assist their teams with training, career development and morale, and can escalate concerns or disputes to senior officers for resolution. This role is performed in addition to rostered watch duties.

Crew Structure

Crew typically work to a one-on, two-off pattern, with their on-watch period will be at an assigned station. One of their off-watch periods will be balanced between training and leisure, while the other will be reserved for sleep.

Secondary posts for alert conditions are assigned to off-watch crew so that they can augment on-watch crews. Those on their waking off-watch (usually immediately after their on-watch) are expected to fill secondary stations to support on-watch crews or join additional crew teams required by the alert condition.


ZoeL's picture

I'm just curious why there are only officers and no crew in the science department?

mattm's picture

It's assumed that the science team wil be made up of officers or warrant officers, given the qualifications needed for these roles. Technical support for science systems (sensors) will be provided by a core systems team from engineering.

Does this assumption sound right?

Alfisti's picture

I think six hour watches are a good idea, as having the crew rotate through the watches means that no-one gets lumpped with a "bad" watch week in and week out. It also means everyone has a chance to interract with those still working on a day/night rhythm (eg. writers or the ship's NAAFI equivalient). Out of curiosity is there likely to be a defence watch (sort of "in-between" watch setup - I believe the RN runs 12 hour watches in this state with half the crew closed up for action and half the crew resting) which would allow the vessel to maintain a state of heightened readiness of an extended period of time?

mattm's picture

You're right, how to deal with extended alert conditions needs more thinking. Current alert conditions assume the most senior and qualified crew take over - for extended periods it would be better to get a mix of experience and seniority, rather than have all of the senior people roll off watch for rest.

Alfisti's picture

I think it probably depends on the alert condition, as Defence Stations would probably still be a step back from action stations. Assuming then that the bridge would require at least two or three personnel at each station when fully manned (eg. Tactical Officer and an Assistant TO), you could possibly split it up so that instead of standing six hours in eighteen, people were standing six hours in twelve whilst on defence watches, then pair of the ATO with whoever normally stands the third watch, and the TO with, say, a gunner's mate or other experienced rating (this actually becomes more difficult to balance without at least a few midshipmen to scatter around the place). Six hours on and six hours off would obviously be hard on the crew (or, take the RN approach and extend it to twelve hours on and twelve off - and bear in mind navy vessels would keep that up for months on end when in an active war zone), but it at least allows some rest whilst keeping the ship in a heightened state of alert.

mattm's picture

Thinking on mess operations (meal service) is to have this managed continuously synched to the watch system. Meals would be served for a period half an hour before and half an hour after the watch transition. This would allow those coming onto shift to get something to eat before they start duty and those coming off to get something to eat when they finish their watch.

Current thinking is that there will be a common dining area for the entire crew - no separate wardroom for officers. It's recognised that officers will need a dedicated area where they can freely discuss vessel and crew management issues - this will take the form of a common office/working space.

Alfisti's picture

I think that's probably the way to operate it in terms of working around the watches. Question is: how do you organise the midnight meal? Presumably breakfast, lunch, and dinner would all be catered for per normal, which is three watch transitions, but what about number four. Do you a) run it like lunch, which would mean essentially needing to run a watch system as well? Or do you b) basically make it a cold meal of sandwiches etc. prepared in advance, which would mean being able to reduce crew size (and thus bunking requirements, consumables requirements, etc) by only having a single shift (maximum two) in the galley?

When thinking on that it is probably worth considering three things: first is thatthe watch system is set up so that no-one is going to be coming off-watch to sandwiches day in and day out. The second is that the kitchen crew, even if it was on watches, wouldn't be able to follow exactly to the same rotation as the rest of the ship anyway as the last thing you want to be doing is trying to switch over personnel in the middle of service. The third is that a lot of kitchen work, particularly during service, is basically run on muscle memory (which is why back of house seriously considers stabbing anyone who wants modifications to their order as it throws that off. Seriously, just pick the tomatoes off), so its one of the few places it is probably better to let people work the same slots day in day out.

As you can probably guess my leaning would be toward running a reduced number of pannels in the galley. Say, two eight hour watches, handing over after lunch service; which gives the watch doing breakfast an hour to get in and cook, and those doing dinner service two hours after to clean up and do prep for breakfast the next "day".