Aft Cabin Design Considerations.

 

Furnishing CTQs

 

The overall design of the aft-cabin is according to the van de Stadt ( VDS)  drawing  634 11-1 ( 26-3-2003).  The only major variation from the drawings is the access, from the technical room, to space under the centerline cabinets.

There are some 3-D images  1,2,3,4

 

Emergency/Safety Equipment

  1. Through hulls. There are no thru hulls in this section of the boat.
  2. Firefighting canister on top of port closet
  3. Handholds ( see later )

 

 

General Construction

                        Light weight plywood.

Finish

                        Painted wood. No sharp corners

 

Cabinetry and fittings

                        latches and pulls

 

Color scheme.

            Black, white and brushed stainless steel, are the three primary finishes that we are using inside the boat. Within that group variations in ”white”, “black” and “brushed stainless” are allowed. The final colors are yet to be decided. Basically all surfaces will be whitish with black trim. There will be a decorative trim on the floor.

 

 

 

 

Electrical

                The aft-cabin has one power/interface box in the aft wall cabinet  between the two bunks.. It controls

1.      lighting in the Aft-cabin

2.      fancoil units in the Aft_cabin

3.      Some radar and other transom mounted devices.

 

Lighting

1.      Safety/Night lighting. There is safety lighting all the way around the base of the cabin furniture at the lowest two floor levels. ( see description of the Floor ).  They are under computer control.

2.      Area lighting. Area lighting is provided by a 24 vdc 30W fluorescent fixture above the cabin door. It is switched from next to the cabin door. The fluorescent fixture must accept bulbs with a color temperature of 3000K. Some units required custom bulbs that do not come with a choice of color temperatures. We want to use a low ( i.e. reddish ) temperature bulb.

3.      Functional lighting. There are numerous functional lights in the aft cabin.

a.       Bed reading lights. These are incandescent lights on swivels. They have integral switches .

b.      Cabinet lights. All cabinets have one or more white LED lights that operate when the cabinet is opened.

4.      All lighting connections are to be made to the control box between the two bunks..

 

 

Heating and AC

 The aft-cabin has one fancoil units. It can be set up for either heating or cooling. It drains ( AC mode ) into the aft head sump pump ( is there sufficient slope? ).  The fan coil inlet is in the middle step. The unit is in the cabinet unit against the aft wall and the exit is from a grating in the top of this cabinet.

Ventilation

There is one hatch in the sidewall of the cockpit and  one VDS Dorade in the roof of this cabin as well as one porthole and one door. The Dorade is equipped with a bi-directional muffin fan.   In good weather the cockpit hatch can be used. In modest weather we can use the Dorade  and leave the cabin door open. The cabin will be equipped with 24 vdc outlets for additional fans. The normal airflow for the boat if in through the forward hatches or Dorades and out through the pilothouse. When the boat is “shut up” because of bad weather, or we are trying to heat or cool the boat, then the primary venting mechanism will be the Dorade in the aft cabin.

 

 

Noise Control

             

 

Continuous sources

1.      Electrical systems in technical room , primarily cooling fan and pump noise.

Semi-Continuous Sources

1.      Generator noise from the engine room. This is expected to be on most of the time.

2.      Saloon/Galley Noise, including the fridge/freezer noise.

2.      Dorade fan noise. If this fan is “on” then it is on continuously.

3.      Fancoil fan noise. If this fan is “on” it is likely to be on continuously but we might put a speed control on the fan, which will change its impact.

Intermittent Sources

 

1.      Main engine noise. There is nothing much we can do about this, other than to supply earplugs.

2.      Propeller noise. Earplugs.

 

We need to protect the cabin from the continuous noise sources as much as possible. This is the primary role of the acoustic insulation between the technical room and the aft cabin. Genset noise is supposed to be handled by the engine room acoustic insulation.  Noise from the Saloon/Galley area can be handled by shutting the aft cabin door if that partition has some acoustic attenuation properties. Fan noise from inside the cabin can be attenuated by the choice of the fan and by using soft surfaces wherever possible.

 

 

Ceiling

  The ceiling is in the same as in other parts of the boat interior. It is made of a soft whitish material with the ceiling panels running longitudinally, separated by off-white strips. There are no lights built into the ceiling. There is a possible issue with headroom in this cabin. Not shown in the VDS drawing is the air duct for engine-room air. This may constitute a hazard for hitting your head. If so then the ceiling deign must minimize this risk.

 

Hatches and Portholes.

 

Any hatch or porthole that is designed to be opened is equipped with removable  anti-mosquito screen  and a Lexan double-walled insulator panel, and privacy blinds.

 

Floor.

Floor panels must give access to the space below and be lockable to survive a 360 roll. In the aft cabin the size/shape of the floor panels are dictated by the design of the cabin. Each level of the exposed cabin floor can be one panel.

The interior of the cupboards on the port side of the cabin need to have floors. These floors need not be removable . (I believe that if the floor outside the cupboard is removable then the area under the cupboard floor can be readily accessed.)

We certainly wish to store stuff under the portside bunk, however it might be more efficient use of space if the “floor” under that bunk were made of netting

The floor under the centerline bunk must be removable but it can follow the levels of the cabin floor. This section of floor is directly over the propeller so it needs to be firmly attached.
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


The figure above shows the three floor levels in “hatched” black. The blue are is, I believe, on a slope. The red line indicates those parts were we want to recess the bottom of the furniture to allow for LED lighting. This type of indentation is shown in the 11_11.dwg /Frame 12 for the galley bench. The VDS drawing of the aft cabin do not show these recesses but we want it.

The solid black line indicates the normal decoration that we expect to put on the floor. Usually this also indicates where the removable and fixed floor meet. There is no black line through the blue area.

 

Hull.  Where the hull would be exposed, ( primarily on the port side of the port bunk )  it is covered in strip planking ( and a soft covering?? )

 

Handholds

The retaining rail on both bunks each have two handholds. These may not be visible in the 3D images or the VDS drawing but they are there.

 

Furniture

 

  1. Saloon/Cabin Door

The cabin side of this door is one big mirror ( not glass, plastic film ). The door provides acoustic isolation from the galley/saloon noise.

 

  1. Port Side Closets .  Once some experience has been gained on how, in practice, closet space it being used then it may be necessary to rearrange the closets. This needs to be kept in mind when the internal structures of the closet are being built. The more forward of the two closets will be used for hanging clothes.  It will not have drawers or shelves.  The more aft closet will not be used for hanging clothes at all. It will be devoted to shelves and they will be built around commercially available plastic containers. .( Storage containers )  A mixture of Rubbermaid models 4603,2282 and 2281 seem possible here. The supporting frame inside the closet must prevent the containers falling out when the door is opened.

I infer from the VDS drawing that both closets go to the ceiling.. We might rethink that and make only the more forward of the two closets go the roof. Where the closet(s) do not go to the roof. the top  must be fiddled and here we intend to locate a fire extinguisher. The height of the closet/fiddle must be adjusted to gain access to this device.

In the VDC drawing the door has square corners. They are to be radiused at 25 mm and edged in black. This is the normal scheme we use throughout the boat.

As in other parts of the boat the lowest ~10cm is recessed to allow for LED lighting

 

 

  1. Center line Closets… These closet will have shelves, not drawers and be designed around commercially available storage containers.  A mixture of Rubbermaid models 4603,2282 and 2281 seem possible here.( or equivalent )  The lowest floor of the closet is not removable. Access to the space under the closet is from the technical room.

These doors in the VDS drawings has square corners, in fact, they are to be radiused to 25 mm and edged in black. The foremost cupboard door may have a different design than the others. There purpose of this design change is to provide a readily accessible space for the person in this bunk to place small items conveniently nearby, e.g. glasses, tissues, medications, book( 1 or 2 ), flashlight. One solution could be to build a shelf into the door, accessible when the door is shut. We cannot build it on the outside of the door as that might present a head hazard. If we choose this solution then the interior shelving of the foremost cupboard will need to be adjusted.

 

 

 

  1. Aft Wall Cupboard. This cupboard contains the fancoil unit and the electrical connection box. It has a structure on top to house the vents and a 230 vac outlet. ( see 3D drawings )

 

  1. Port Bunk. The bed is designed for one person. The bed structure needs to include support for lee clothes. The bed platform must be removable to give access to the space below.  The wall of the bunk is recessed at the middle floor level to the height of the middle step.

Note that the retaining wall of the bunk is to be radiused, not square edged.( We are having problem with the CAD package)

 

 

  1. Port Bunk shelf.  Can we put a small shelf in the corner between the wall of the closet and the hull? The purpose of the shelf is that same as described for the centerline closet door.
  2. Port Bunk head board.. This is upholstered to a height of  XX cm above the mattress and above that supports 2 bed reading lights.

 

 

  1. Centerline Bunk Bed

This is for one person. The bed platform must be removable for access to stuff underneath. The wall of the bunk is recessed at the middle floor level to the height of the middle step. Note that the retaining wall of the bunk is to be radiused, not square edged.( We are having problem with the CAD package)

 

  1. Centerline Bunk Shelf.

 

There must be some place for small bedtime things. We made one suggestion for this above.

 

 

  1. Centerline Bunk Headboard.

This is upholstered to a height of  XX cm above the mattress and above that supports 2 bed reading lights.

 

11.  Furniture and Floor Hardware. The doors and drawers are fitted with push-pull hardware and the hinges are hidden. The floor panels are either screwed in place or locked down. Southco hardware (http://www.southco.com/products/html/new_products.htm) is of the type considered here. 

 

Bilge Pumping.

    

None.

 

Equipment locations

 

There is very little fixed equipment in the aft cabin. The breather filters from the diesel day tank and the main tank might come into this space. Under the lowest of the floor levels there will certainly be electrical cables and possibly fridge/freezer tubing.

 

Electrical Installation, Including Computer Networks

 

Network and interfaces.

 

            There are USB and Ethernet  ( U&E) cables to both bunks.

 

24 vdc & 230 vac Electrical

In addition to the network cables there is a 24 vdc outlet for each bunk. There is a 230 vac receptacle in the aft cabinet , and another 24 vdc connector.

 

It is suggested that there be a standard outlet panel near the head of each bunk. We would propose using the same connector panel in several other locations throughout the boat.

The panel would contain 1 ethernet connector, 2 USB connectors and a 24 vdc connector. The panel would constitute the faceplate for a connector box. The connector box would be a conventional plastic box from an electrical supply house. Care should be taken that it is deep enough to allow cabling to the connectors on the faceplate. The faceplate in the image is about 10 cm square
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


                                                                                                                        Figure 1

 

The overall electrical diagram is shown in the image below. ( fugure 2 ). It shows 2 outlet boxes of the type described above. One at the head area of each bunk. The schematic shows a number of cables going from the aft central cabinet to these boxes:

1.      a 24 vdc power cable. This is to be color coded red for the +24 and black for the 24 volt return. The main 24 vdc electrical installation follows the same color convention. I would suggest AWG 16 for this cable ( I think this is close to your ISO 1 mm^2 cable size )

2.      two USB cables. We will try to use the made-up cable you can buy in the stores. Cables of 3 meters in length are readily available, maybe even longer. However I do not want you to go to enormous lengths to find a cable path between boxes that is less than the available cables. If necessary we will simply lay the cable an I will add the connectors later. Here is a reference to this cable type from a company called L-COM in the US.( http://www.l-com.com/jump.jsp?lGen=detail&itemID=7554&itemType=PRODUCT&iProductID=7554)  I presume that there is a Dutch supplier or you might try Bulgin ( UK). Even  using the commercially made up cables where we can I believe that we will be using a good bit of this cable on the boat so I suggest that you buy ~100 meters.

3.      Industrial Ethernet cable. It contains 4 twisted pairs. Belden is a common supplier of this cable over here. Most of the products seems to be solid wire, which I wonder about in a vibrational environment, but there is a stranded version ( Belden 7924A) . Carl suggested a shielded Ethernet cable but I have not been able to find one.

4.      A control cable. This is for signals and not power. I suggest a shielded cable with 4 pairs ( eg the Belden 85164  As shown in the diagram this control cable has no connection to the front panel of the outlet box. We will probably use for push buttons on the front panel.

Cables 2(2),3 and 4 may be bundled together but the 24 vdc power is separate. On the side of the hull there are two cable trays one for “power” and one of “signals”. Put the 24 vdc cable in the “power” tray.

In addition to these outlet boxes near the head of each bunk the diagram shows two more 24 vdc junction boxes. One is in the more forward of the two port-side closets, toward the roof, and the other is in the centerline closets. The 24 vdc cables to these junction boxes are of the same type as in 1 above. Out of these boxes come cabling for lights e.g. the fluorescent light fixture, the reading lights, and the LED lights in the closets.

 

                        There is a 230 vac outlet built into the top of the aft cabinet. It has a Ground-Fault_Interrupter receptacle and a snap over cover.

 

                        There is a 24 vdc fan associated with the Dorade in the roof of the aft cabin. The same cable type as for 1 above can be used. Controls for the fan ( direction/velocity )  will be in the aft cabin cabinet . The placement of this fan needs to be discussed. It has not yet been determined what will be the size/shape of the Dorade air outlet into the roof of the aft cabin. This fitting must come with the ability to be shut off in bad weather and yet not allow the fan to be immersed in seawater. One type of fitting I would suggest is an expandable pipe plug (http://www.newmantools.com/cob/alum.htm )

 

                        There are two strings of red LED safety lights as described above, basically along each side of the cabin floor. In addition at the foot of the door, to show people where the bottom of the door is, there is a red LED on either side of the door.  The strings of LEDs will be DHM supplied. At the end of each string will be a 24 vdc cable. There needs to be provision to bring these two cables back into the aft Cabin control box.

           

The fan coil unit for the aft cabin is in the control box so wiring for it is not shown.
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


                                                                                                            Figure 2