I am having a go at an HO scale scratch build very strongly based on the public warehouse,In the now out of print Kalmbach book Easy to Build Model Railroad Structures starting on page 86.
For ease of construction I have chosen to square up both ends making it a much simpler wedge shape,and foam core board for the construction of basic box part of the structure. With card forming the detailed skin of the structure.
I have a couple of dimensions I cannot determine or work out not being familiar with US building regulations and practices they are not on any of the drawings nor it would seem mentioned in the article.
They are as follows the hight of the parapet wall over the roof, the size of the I beam between the ground and first floor of the warehouse.I would also appreciate any suggestions as to what grit sand paper would look right for the HO scale flat roof.
I cannot answer those questions on that specific plan. But in general, in those situations I scale out the drawing. That is take a known dimension on the plan and get the drawings scale by comparing actual measurement to the stated prototype size stated on the plan. Of course the plan is in HO scale or 1/87, then you can simply measure and multiply, so if it’s a 1" measurement, then it would be 87" for the prototype. . An HO scale ruler is very helpful in buiilding scale structures, vehicles, etc. so that you can just lay it on an undimensioned section of an HO plan and read the prototype dimensions from the ruler.
Parapet wall? I assume this is a flat roof building where the exterior wall rises somewhat above the level of the flat roof? Having been out on a number of flat roofs, doing maintenance, I can say that the exterior wall (parapet?) is knee high to a person standing on the roof. High enough to keep loose stuff from blowing off the roof and smashing down on passing pedestrians, high enough to give workers a sense of security while up on the roof, but no higher. In winter snow will drift up to the height of the exterior walls, adding load to the roof, and when it melts, the melt water will find the least unsoundness in the roofing material. So no one makes them higher than necessary.
Size of I-beam between ground and first floor? Are you talking about a vertical column holding up the first floor? Nobody uses I-beams for vertical columns. An I-beam is strong only in one direction. Bending loads in other directions will readily cause it to buckle. A column has to resist bending loads in all directions, which is why columns are round.
Or are you talking about I-beams used as floor joists? Or main beams? Common practice is to run a beam the long way down the center of the building and lay smaller joists (often wood) from the main beam to the exterior walls. Such a main beam might have a web a foot or two feet deep. Smaller joists, if steel, might have a web of half a foot.
I have used 220 grit carbide (black) sandpaper for roofs with good results.
Using a HO scale ruler, the I beam is 9 inches deep.
The roof drain shown on the wide end of the building is 12" below the top of the building. This would be at the same height as tjhe roof surface making the parapet 12" at the drain. However water will not drain properly from a flat roof so the roof must be sloped toward the drain or be designed to support the weight of water accumulated. Probably the 12 inches parapet is OK but very minimal (see dstarr’s comments) if the roof is designed to support the water weight. However if it is not designed to support the water weight -Assuming a 2% slope (minimum slope per code in many parts of the USA) toward the drain the roof surface would be at least 16.8 inches higher at the narrow end of the building.
Another problem with the plan is there is no space for the roof structure. Assuming 12 inches additional height is needed for the roof structure, the " first floor" would have to be 29 inches or more taller to accomodate the roof and slope The parapet would raise the total height even more. This really changes the appearance of the building.
It is unlikely that one roof drain would be adequate. I would put 2 to 4 drains on one of the long sides and slope the roof toward them. The higher side of the roof would then be less than 4 inches above the lower side.
Assuming the the “first floor” structure includes I beams attached to the 9 inch I beams shown(probably attached using angles and rivets) the “first floor” structure is probably OK.
Despite all of the above I still like the appearance of the model even though I know it is not possible in the real world. Over 40 years ago I built a model based on the plan. That was before I studied Architecture and Engineering and recognized the problems with it.
Nobody uses I-beams for vertical columns. An I-beam is strong only in one direction. Bending loads in other directions will readily cause it to buckle. A column has to resist bending loads in all directions, which is why columns are round.
[quote]
Although many structures use round columns, they are not typical. I-beam and wide-flange steel shapes are used extensively for steel columns, especially wide-flange shapes. They do have some strength in both directions. Properly braced at appropriate heights and in appropriate directions, they are fine as columns.
Thanks for the speedy replies and helpful information.
The I beam for the person that asked runs around the middle of the structure with brick work sitting in it, I am guessing on a real structure there would be internal steel work as well.
Looks like I had better stick another thickness of foam core board on the base to get the extra hight for the walls and remember to cut the card wall sheet a bit higher before adding the overlay of details.
I am thinking of calling it I.L. Lisit and Co secure storage and having the law paying the place some unwelcome attention.
Which brings another question who does the good quality HO US police cars or better still the more expensive ones with working flashing lights for visual interest.
I ordered a scale rule today, where can I get a modeling sized steel? brass flat square the local suppliers only have plastic ones
I was told I needed a specialist hobby tool supplier for what I wanted as they did not sell metal ones any more, some sort of safety concern I could not make sense of.
I will be having more and more of the scratch build lark I find it rather enjoyable should have started properly years ago.[:$]
Can any one suggest a suitable substitute for shellac to soak the manila and corn flakes pack card outer layers in to harden and seal them, before the skin layers are applied (After drying!!) to the base foam core structure.
I cannot find any at the local hard ware shops apparently “no one uses it much any more” a response I found rather surprising
Gidday John, if your’e referring to a steel machinists square, any reputable engineering tool supplier should have them in stock. I wouldn’t be without my 4 inch square. As for drawing squares I’ve only ever seen plastic ones.
Have 2.5" 4"and 7" engineers squares what would be far more useful given the use of card and foam core board ( Old fashioned may be but cheap and easy to work with [:D] ) with is a flat square.
It looks very similar to a set square but is made of steel but does not have the graduations you would find on a drafting set square.
It’s very common on engineering marking out tables, but I have never been able to find one in an engineering tool suppliers.
Well the building progresses the core block is done the first two layers of card are on both ends of the structure a third for the parapet walls sand paper roof cover is on.
I dread doing the timber siding and block work, going to do individual blocks and planks in card a pain but hopefully worth it.
Am working on the first side and have noticed an unintentional bonus the roof isn’t flat it has a slope on it, that I will have to watch for when I put on the down pipes
As the structure slowly takes shape a concern has arisen the lack of detail bits on the roof.
None are shown on the plan should some form of ventilator or something be on the roof it seems odd there is nothing other than the roof and the parapet walls up top
Given that it looks to be a large ish structure particularly when seen side on and will predominantly be viewed from an angle that the roof will be in clear line of sight, it seems something even if only a stove pipe for the office should be on the roof
Gidday John, was in the local branch of Bunnings today and out of curiosity had a look for squares. They had a range of flat carpenters metal squares 600mm x 45mm from $19-95 upwards.
Nobody uses I-beams for vertical columns. An I-beam is strong only in one direction. Bending loads in other directions will readily cause it to buckle. A column has to resist bending loads in all directions, which is why columns are round.