Hi everyone:
I have finally started construction on my new railway - four years after dismantling my former railway and moving to a new house. The new railway is on the side of a rather steep hill and it requires a couple of dogbone bends (10 foot diameter) and about a 3% grade to make it to the top plateau. It's kinda cool!
My concern is that one of the dogbones requires a curved trestle or segmented bridge that rises over four feet in height. Frankly, I am concerned about a possible derailment and a spectacular crash. Do you have any advice to minimize this risk? I've considered adding railing or possibly making some sort of segmented truss bridge (to accommodate the curve) that keeps the rolling stock on the bridge/trestle.
Just looking for opinions and insights.
Thanks.
SoCalJoe: First, welcome to the forum. Second, If you had a bit more data in your bio, i.e. your location, someone might be able to better guess your climate and such. Why climate? You ask, do you have gentle breezes blowing up your hill? Or hurricane force winds? I suspect from your name you live here in SoCal. I’m going to guess light breezes. If so I really wouldn’t worry too much. Just ensure you have a well-built and stable bridge, ensure the bridge deck is continuously smooth and that your rails are secure and that all joints are smooth and solid. I would recommend long "flex rails" with joints well offset using rail clamps. If your rails are smooth and solid you should not experience any derailments unless you have some sort of aerial assault (a.k.a. "attack crows") or foreign object debris on the bridge. If you have not enough faith in yourself you could always construct walkways on each side with siderails.
Tom Trigg
Thanks Tom:
Yes, I live in Simi Valley, Ventura County. We get some strong Santa Ana winds and some days it will blow too hard for operations. The railway site sits on the upper side of a ravine so the wind can really whip through it.
Another consideration is possibly future live steam operatons. I've got an Accucraft Ruby with a remote control throttle installed. It can be quite temperamental and I have visions of catastophies on this trestle. Frankly, it may not make sense to run it on this part of the railway, given the trestles and the elevation change. Phase 2 of the railway will be the construction of a flat line with wide curves. I may relegate my live steam operations to that. We'll see as I gain more experience with live steam. The majority of the time will be with electric.
Thanks for the advice. I'll heed every word of it.
Joe
Howdy Joe welcome aboard. I live on the east slope of the Sierra Nevada in a valley I later learned had an Indian name meaning “Valley of the Seven Winds”; they can all occur in one day. I have a ten foot long trestle on a 12.5’ curve and 2.5% grade. In addition to Tom’s suggestions I would add that planting vegetation, like thymes, would allow for a softer landing. I plant Wooly Thyme and Lemon Thyme on our railroad.
Have fun, Rob
Thanks Rob. Great idea! I have another question for you regarding your 2.5% grade on the curve. Does this negatively impact your ability to pull your rolling stock uphill in a noticable way? I planned on eliminating the incline on my dogbone curves, but adding a slight grade, even 1.5 to 2% on the curves would allow me to reduce the grade in other places.
Thanks,
Welcome to the forum! If you live in Southern California, I think you might want to make sure the trestle can surive an earthquake. Hops this helps. - Peter
Modeling the Bellefonte Central Railroad
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Joe: All curves and all grades above 0% will impact on the length of your consists. The tighter the curves and/or the steeper the grade the more the impact is. A grade on a curve is a double whammy. Keeping the grades to less than 2% and the curves to 10 ft. or larger will produce acceptable results. When designing you empire the decision to go with tighter curves (see the posts on Vic’s pizza) places limitations on length of the equipment (Vic is limited to 2 axle equipment and has done quite well.) Running on higher grades can be done (check out my trolley line videos over on the video section of this site.) My bridge has varying grades, the approach 4 ft dia with 3~4.5% grade, lower end of the bridge is at 14% then after a 18 inch radius "S" curve the grade quickly increases to 17.5%~19%. When I designed this route I took into consideration that I would have to replace the equipment at extremely short life spans. I guess what I’m saying is that all the "rules of thumb" for grades and curves can be seriously violated, so long as you know what the limitations will be in advance and are willing to live with the limitations. Since your design calls for 10 ft curves and 3% grades, it is a very doable thing. You can lighten the weight of your cars, thereby increasing the number of cars a single engine can pull. The trade off there is lighter cars are more susceptible to being blown off the bridge by the wind. In that case I would suggest some truss work on the bridge.
Thanks Tom. Since the height I must navigate is fixed (concrete driveway and concrete retaining wall) anything I can do to add track length or or a bit of grade on the dogbone curves helps keep the overall grade manageable. Even a 1-2% grade on the curves helps.
Howdy Joe; Tom gives a good dissertation on grades and power. I model 1:29 and run all my trains with at least two units (4 motors) and up to about 18 cars (not counting locos or caboose) on 10’ minimum diameter curves and 2.5% grades max. Over that train length I find adding a rear or mid-train helper(s) adds more power and relieves coupler strain and streamlining.
Good luck, Rob
Joe, give this a try. Get a correct measurement (in inches) that you need to climb (the vertical height ONLY, i.e. this abutment is six inches elevation higher that abutment), now multiply by 105. You now have the total length needed for your bridge with a grade at or just below 1% grade. (The extra 5 gives a margin of error allowance.) Grab the garden hose and measure off this distance. Take the hose over to the gap you need to span. Push, pull, or twist the hose in place keeping curves at or above 10ft diameters. You now have the "centerline footprint" for your new bridge. Drive a bunch of "construction stakes" along the hose and start to build the new bridge. Your bridge will have a 1% or less grade and should give many hours of enjoyable operation.
Thanks Ray:
You got me thinking so I revisited all of my planned switches. I should be okay as they all should hug the hill. I'll try to make the track bed wide enough to accommodate a derailment.
I got a line on free fill dirt this weekend and moved three pick-up loads. I had not planned on adding earth this soon is the process but opportunity knocked. Now that I've got some dirt to play with, I'm tweaking the line here and there. With the steep side hill, I am concerned about maintenance access to all of the line so I am planning foot paths and stepping stones as well as the track. One issue I've noticed is that it's easy to block off the inner circle of a loop if you are not carefull. Place a three-foot high trestle that loops back into a hill and you can be left with an inaccessable area in between. I think I'll install a removeble truss bridge to gain access.
That leads me to another question. How do you guys handle removable bridges and track sections? In particular, how do you conveniently detach/re-attach the track? I have a section that seldom requires detachment (the loop I described above) and I've got two sections that require it every time I run the trains (in and out of the workshop).
Howdy Joe; I have a situation where my mainline runs through a storage yard under our house. I adopted a system we used at a HO modular group. We used “spanners” between modules. A spanner is a track section under cut on one so the track joiners slide under the ties. Then the spanner is slid into place on the conventional end. Then the joiners on the under cut end are slid into the track at the other end. The process takes less than a minute.
In reference to your question about removable bridges, mine is actually hinged, but the same idea for a totally removable one would be the same. I use the type of rail connecter that is made for drop in bridges on the non-hinged end. the bridge rail simply drops into the rail clamp for alignment. Keep in mind the change in rail length due to temperature changes. Electrical continuity for the bus is accomplished using 4 wire trailer light connecters (I have dual mainlines). They work well because they are weather resistant and there is only one way to connect them avoiding operator error. If you set your track blocks just prior to the gap, with this set up, you also avoid a crash into a missing bridge hole. A little electric conductive grease every once in a while and you are good to go.
I tried track clamps made for lift out schemes and found them to be quite cumbersome. I went back to the “spanner” principle as in my above post. I also forgot to mention I have permanent electrical connections on both sides of the spanner location. I have two spanners on my railroad and found them to be cheap, easy to install/remove, and efficient.
Thanks guys:
I researched the removable rail clamps and found the Split Jaw ones at $30 a pair. Since I would need quite a few of these, I fabbed up a couple of spanners as a "proof of concept". I think they'll do the trick for my needs.
Hmm, I have a 12 foot lift out section with Hillman lift out bridge clamps. I pick it up and put it back in place by myself, no problem.
The distance between the two vertical brown pipes is 12 feet.
Regards, Greg
Visit my site: http://www.elmassian.com - lots of tips on locos, rolling stock and more.
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Greg, that's interesting. I see that the Hillman's clamps are $18.95 a pair verses the Split-Jaw at $30. I may have to try them out.
I use conventional 332 Hillman clamps on my regular track work and they work very well. However their “bridge” clamps didn’t work well for me. First off you have to back the set screws off to get the bridge track into the slot. Next you have to tighten the set screw to hold the track in position. Third I’ve had the track pop out of the clamp while operating. I’ve never ever had a problem with spanners, mechanical or electrical. I use two spanners every time I operate my present railroad; over ten years. I and a jillion other modular operators have used them since the inception of modular railroading. They are dependable and cost is zero.
The split jaw are "on sale" for $20 a pair last time I looked.
I have both types.
The hillmans work better for me. I've had a number of make the same comment as Rob.
You have to adjust the "set screw" to give enough tension to hold the rail in place, but loose enough to let the rail come out.
I have not adjusted mine in 2 years.
But, they will not take torquing or flexing or the rail can indeed pop up.
But a well designed bridge or liftout section will not put all the force on the clamps, since you can bend up the ends of the rails.
As I said, that's a 12 foot length of 2 x 4 with a wire and turnbuckle under it to keep it from sagging. I grab it in the center to remove and replace, 6 foot away from the clamps.
I tried the split jaws and they work like Rob describes for me, they don't seem be designed to clamp tightly on one side but still allow the other side to snap in and out.
My hillmans are also nickel plated, so that is why they are in silver in the photo.
This is how I did mine. I plan on upgrading by adding half sections of jointers to the bridge. this will eliminate the wheel hop I have crossing the bridge's.
The above bridge is still in use, but at a much lower level
The head is gray, hands don't work , back is weak, legs give out, eyes are gone, money go's and my wife still love's Me.
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