BENCHWORK THEORIES (1) - BUNKER PRINCIPLE

• Can survive direct hits from SCUD missiles.
• 4 x 2 trusses supported on a forest of legs.
• Often over built, costs a lot and uses more resources than necessary (including time!)
• Tends to waste space.

BENCHWORK THEORIES (2) - TENSILE PRINCIPLE.

• For HO or smaller scales.
• Narrow grids of 2 x 1s bolted to walls.
This approach allows a layout to be constructed around the walls of a  2 car garage and still leave room for a car, storage and workshop.
 
• Few legs - relies on diagonal braces.
If built in a spare room, leaves room for a computer, sewing machine or spare bed.
 
• Quick, cheap and easy to build.
• Maximises under the layout space - room can serve 2 or more functions.
This will allow the biggest possible layout with the least possible impact on other uses.

 
MINIMAL BENCHWORK - THE RULES

• Plywood or spline roadbed - not MDF or chipboard sheets.
Unless you know what you are doing, MDF and chipboard tends to be heavier and less dimensionally stable than even second grade ply.

Modellers often blame “rail” movement on temperature variations. However this movement  is often the result of changes in humidity causing relatively large changes in benchwork timber dimensions.
 

• Avoid straight track where possible.
Straight track will kink when benchwork moves. Long sweeping curves absorb most expansion and contraction without damage and they look better too!
 
• Screw & glue benchwork.

ASSEMBLE THE GRID UNIT

• 2 x 1 timber (rear member can be 3 x 1)1.2m to 1.8m long
Rear member can be deeper to give stronger mounting.
 
• 0.3m to 0.6m wide (except for return sections)
Think of the units as being reusable and transportable.
Not really suited for deep scenes - though sections can vary in width to give a pleasing free form fascia.
• Space cross members for access
Power tool access between cross members is required
• Use jig or picture frame clamps to assemble

MOUNT THE GRID

• Ramset or Rawley plugs for masonry walls
• Coach bolt or screw to timber studs
• Diagonal brace strongest option
Diagonal braces do not have to go all the way to the floor.
 
• Legs take more room
If you do use legs remember to set them back to allow for toe room.
• Grids can be screwed/bolted together so only every second unit is braced.
You may want to bolt units directly together in which case David Burrows domino sections may be applicable.

However, I find the extra wiring and track joins to be too much work. I prefer to strip the units when I change a layout.
 

• Engaged piers.
If you have engaged piers think about mounting units separately between piers  and spanning the pier with the road bed and a fascia.

 

RETURN END UNITS

Must be wider

Use backdrop as support web


 

PENINSULAS
• L girder is superior to grids
L girder construction more is more practical in peninsulas as the grids are too flimsy for long spans.
 
• Long spans possible with 4 x 4 L girders
On very long spans you can make the backdrop out of 18mm ply and create an inverted T-girder to strengthen the span.
 
• Very long spans - use backdrop as girder
The cross members used with L girders allow free form benchwork and radial support for curved track at peninsula ends.

Tracks turning 180 degrees will look convincing if changes in elevation are used to justify curvature. The grades need only be slight.
 

Peninsula legs can be located a quarter to a third of the way along the span to maximise strength.
 
• Legs can be 3 x 1
• Bolt legs to floor with brackets
• One third span rule

 

DOUBLE DECKS
 

• Upper deck support
The support for the upper deck should not be obvious.
• Use narrower grid
Narrower upper decks give a better view of the lower deck and do not intrude into line of sight when operating lower deck.

Because the upper deck is higher the reduced width is not that obvious.

• Mount to wall
• Attach bottom bracket as per normal
• Attach top bracket with 3mm gap for extra stiffness
The air gap between the upper shelf bracket causes the top bracket to work against the bottom one when the screws are tightened, adding pretensioning to the system, significantly increasing rigidity.

 
 
 
NO VISIBLE MEANS OF SUPPORT……..

 
• Hang from beams with 3x1 hangers
• Use diagonal braces
• Use webs
• Will span double garage without legs


 

CONCLUSION

• These methods are not for everyone
• Some modellers consider it an affront to use one skinny piece of timber when four big pieces will do the same.
If your space is restricted and the only way you can justify a large layout is by sharing the layout space with the family car, computer, sewing machine or general storage, then minimal benchwork is likely to result in a larger layout in a given space.
 
• Save space, resources and time
• Vary methods to solve different problems
 
Here’s some photos of my layout and how the space is shared.