As someone pointed out, I’ll want a minimum size access hole on my 5’8" x 10’2" HO layout. During construction, I can have the layout away from the wall so not so critical then. But afterward, the hole, within an upper level reversing loop, will take space away from a yard, so I’d like to keep it on the smallest reasonable size. How big do you suggest as a minimum? I’ve thought about doing a trial box on sawhorses to see what I can manage. I want to resolve for my 1x4 framing plan.
I don’t think there is one specific answer as we are all different size people. Making a test as you have suggested is probably the best way to go.
Um… Er… How big is your belly? How big do you expect your belly to grow before you take this layout down to build another one.
The LION did have an access hole in his previous layout, but no more. LIONS have trouble bending down that low (and getting up again).
The LION does have a table segment 6’ wide x 12’ long, but there is nothing in there and no way to get in there to do anything anyway. And the backdrops are so tall that nobody will ever see the hole anyway.
Oh well, back to your access way, (we do not call them holes–that would be uncouth), you will need to get tools in there as well as your belly: soldering iron, saws, drills, trees, stuff like that.
ROAR
If you can temporarily move the layout out from the wall, I would mount the layout on wheels.
I have a small test layout 5’4" by 12’ on 4" wheels that I can roll out when I need access to the back side.
Good luck
Paul
If, like the Lion and myself, you find surfacing through an access hatch a trial, you might consider using one of those skyhook creepers that mechanics use to access the plumbing on top of 18-wheeler engines. (The alternative is to design to avoid access hatches, which I did but you apparently didn’t.)
As indicated, one size does not fit all. A hatch sixteen inches square would be oversize for my one friend (a former Olympic gymnast about as big around as a baseball bat) but would barely clear my head - and forget about the shoulders.
OTOH, you could, by careful jointing, arrange a cover which could include trackwork. It might mean temporarily clearing the stub ends of some yard tracks before pulling the SSN surfacing at the North Pole maneuver - but that might make the difference between a good size access opening and fugheddaboudit.
Chuck (Modeling Central Japan in September, 1964 - with a maximum 28 inch reach requirement)
Hatch size depends on how much of you is going to stick up. For layouts with relatively high elevations, you can get away with just head and shoulders. If it’s lower, then your gut becomes a factor. My gut is catching up, but like most men, it’s the shoulders that limit me most.
Although it’s a lot trickier to get right, there’s nothing inherently wrong with a liftoff section that has track on it. You will need to have some sort of way to provide power to the rails, and alignment will be very important, but if your hatch is beneath a yard space you will be running at reduced speed so alignment isn’t as critical as it would be on a main line.
I guess I would go with a slightly larger opening with track rather than one that’s a very tight fit without track. I have an access hole right now, because there’s no scenery there yet. It clears my shoulders with room to spare, but it’s still awkward even at that size. The whole process of crawling under the layout and then trying to surface vertically is much more challenging for me than it would have been a few decades ago. When I have to get in there, I always come out feeling old. That may be the worst part.
In my experience, and thank goodness I do not have an overhanging belly, and even though one size does not fit all, a 2-foot square access hatch should do it. That is, 24 inches by 24 inches.
Rich
For construction purposes I made mine quite large and it made getting in and out and working on the layout much easier. I do plan to cut the hole by half when done and hide the remaining hatch with something or other. I had a 29" waist in high school and 34" now at 55. I am full of Arthritis and the only exercise I can tolerate is riding the Recumbent Bike. It is a real battle to stay fit but so far I am winning.
Brent[C):-)]
When I was a teenager, my Dad’s layout had access holes that were about 16"x18" to 18"x24". Although they weren’t fun to use, the real issue is what to do with the tools and your hands and arms once you get up in the hole. If you are going to have details and scenery right to the edge of the hole, then I would say the hole needs to be closer to 36"x36" (or 36" diameter). That would allow you to wear and reach into a tool belt and/or apron instead of laying everything (including your hands) on top to the scenery. Even a roll-around chest that goes under the layout with you is going to need room to get your arms and hands into it. And if you don’t want your elbows or hands or shirt sleeves catching on your fine details, you need extra room for them to dangle when not actually reaching something on the layout.
The other (very good) alternative is to line the hole with a 4" to 6" wide shelf, but this ends up taking nearly the same space as just having a bigger hole. But the shelf is actually the most convenient alternative, just like a shelf along the fascia in the aisle.
my thoughts, your choices
Fred W
I’ll second the recommendation for an overhead creeper. I have one, and it’s very easy to work over my layout. Folded, it stores underneath.
Variables to factor in your eventual construction:
Your shoulder height
Your shoulder width
Your shoulder’s ability to rotate such that you can get your arm above your head if you have to raise up through the hatch that way.
The height of the hatch
How far you must reach/access in order for that hatch to afford you the utility you need from it in all four directions.
What tools/chords you will need to lift and drop through the hatch
Those are the big ones I can think of right off the bat.
Crandell
Unless those backdrops are removable, an access cutout is almost meaningless.
I would offer that an access cutout should at least match minimal aisle width and shoulder width. John Allen did suggest that 12 inches would work on an “emergency” access aisle, but that was in the 70s before we became a big society. His layout designs tended to have large access cutouts.
The best advice, as mentioned previously, was to try it out.
On the LION’s layout that ins NOT an access hole. LION had two tables each 3’ wide and 12 and 14 feet long. Him bolted them together side by side, now him has a table 6’ wide and 16’ long. Him cannot reach the middle.
No matter, nothing in middle. Is an open space. Cannot access it at all not even from the bottom. LION stack boxes of stuff under table, and wrap a curtain around it. Table DONE. Tracks run on the outside 24 inches. Nothing in middle. Top level tracks are about 60" from floor. It will not take much of a view block to hide the hole entirely. But station there is 42nd Street and simply does need tall buildings on it.
The other side of the table is the Coney Island yards. Same view block, different buildings. Nothing for a LION to do in the middle of the layout.
Now all LION needs to do is to build lots of tall buildings on the CHEAP!
ROAR
Out of curiosity, what is the weight capacity of this device?