Traction Tires for Diesels and Electrics?

[Trolleyfan]

A 4% grade is very steep by prototype standards and is a grade that rarely is reached by most railroads without greatly restricting train length. For example: A locomotive exerting 80,000 lbs of drawbar pull can pull 17,778 tons on level tangent dry track. This same locomotive on a 0.80% grade will only be able to pull a train weighing 3902 tons or a little less than 1/4 of the train it could pull on the level. Looking at it from a different perspective, this locomotive would be able to pull approximately 137 130-ton cars on the level but only 30 130-ton cars up that 0.80% grade. You can find the formula to figure tonnage on grades in railroad engineering manuals, but it is probably a bit to complicated for model railroad use and wouldn't be accurate unless you were using steel wheels on steel rail due to the adhesion coeffients used to derive the formula. Other factors that would need to be taken into account to figure tonnage ratings on a grade would include wheel flange to railhead friction, curve resistance and moisture conditions just to name a few.

I think your locomotive is doing an excellent job of hauling those 5 cars up that 4% grade as it is, so rather than spending the money to put a traction tire on it, and possibly burning out the motor, do like the railroads do and add more locomotives. The other alternative would be to decrease the grade to a more prototypical grade and therefore be able to run longer trains with fewer locomotives. I have very few problems running on grades of up to 6%, but then my passenger trains are, at most, 6 cars long and all cars are powered (I model interurbans and streetcars so if it has a pole or pantograph it has a motor).

:ugeek:

[Green_Elite_Cab]

A 4% grade is very steep by prototype standards and is a grade that rarely is reached by most railroads without greatly restricting train length. For example: A locomotive exerting 80,000 lbs of drawbar pull can pull 17,778 tons on level tangent dry track. This same locomotive on a 0.80% grade will only be able to pull a train weighing 3902 tons or a little less than 1/4 of the train it could pull on the level. Looking at it from a different perspective, this locomotive would be able to pull approximately 137 130-ton cars on the level but only 30 130-ton cars up that 0.80% grade. You can find the formula to figure tonnage on grades in railroad engineering manuals, but it is probably a bit to complicated for model railroad use and wouldn't be accurate unless you were using steel wheels on steel rail due to the adhesion coeffients used to derive the formula. Other factors that would need to be taken into account to figure tonnage ratings on a grade would include wheel flange to railhead friction, curve resistance and moisture conditions just to name a few.

I think your locomotive is doing an excellent job of hauling those 5 cars up that 4% grade as it is, so rather than spending the money to put a traction tire on it, and possibly burning out the motor, do like the railroads do and add more locomotives. The other alternative would be to decrease the grade to a more prototypical grade and therefore be able to run longer trains with fewer locomotives. I have very few problems running on grades of up to 6%, but then my passenger trains are, at most, 6 cars long and all cars are powered (I model interurbans and streetcars so if it has a pole or pantograph it has a motor).

:ugeek:

Its generally agreed that the Atlas AEM7/ALP44 models are underpowered. They need a way to pull more. Its looking like the new decoders with Back-EMF greatly improve the pulling power, but these units can pull 13 car trains alone in real life. While the 4 percent grade certainly limits things, the AEM7s can't even do that on level track without some form of assistance. the majority of it has to do with not enough traction due to it's light size. I'm thinking using some of that "bullfrog" snot will greatly improve its ability to run.

[RobertInOntario]

I don't know about diesels, but two of my British steam tender-drive locos have traction tires. To make a long story short, I had to replace the tires on one of them and had a terrible time finding them -- it took a year or so. I finally found a company in Britain that sold just what I needed for Hornby locos.

If you think that source might help, I could probably look it up. Who knows, maybe they sell tires of the diameter that you need.

It was called something like "Hornby Spares" or "Abigail Spares".

Also, if Wahl Oil gets on the track, the tires can easily expand. They become too large and come off. This what happened to my loco and which is why I had to replace the tires!

Rob

[doctorwayne]

There are very few HO locos which don't have room for additional weight, although adding that weight is not always a simple matter.
I built three of these Athearn U-33Cs, ballasting them to just over 33 ounces each:
[album]1360[/album]

For the most part, the weights were custom-cast LINK, although I used some sheet lead, barely visible in the photo below, over the area where the twin motors were located.
[album]1361[/album]

There is room for probably at least another 3 ounces between the rear of the steps wells and the body-mounted couplers.

Of course, decoders do require space that could otherwise be used for added weight. One solution is to replace all or part of the factory-supplied weight with a new one cast in lead, which is considerably heavier than the zinc or Zamac normally used. Here's an example, although it's a steam locomotive. Steam locos, as has been noted, benefit from having the weight balanced about the centre of their driver wheelbase, and, due to the limited space in most boilers, this can require some innovative thinking. At least there's room in most tenders for the decoder. Balancing the weight is the important thing, and can allow a loco to pull more than an identical counterpart that has had weight added but is out-of-balance. For diesels, balancing the weight is not so critical, but you should try to do so, within reason.

Wayne

[RobertInOntario]

1-2 of my Bachmann British steam locos could really do with some extra weight added yet they seem very complicated to take apart. One of these is a Bachmann model of an 0-6-0 Collett. I once tried to take it apart and it seemed very messy -- its driving wheels started coming out of position, etc. (when I took it apart). Once I saw this, I immediately stopped and reassembled it. I thought that I'd sooner have it too light (and being only able to haul 3-4 coaches) rather than not working at all!

Still, I wish I could find a way to add some extra weight to it.

Rob

[Russ Bellinis]

I was going to suggest changing your weights, but Dr Wayne already covered my suggestion. Most locomotives have removable weights installed from the manufacturer, but by replacing the steel or zamac factory cast weights with lead, you can add significant amounts of weight without modifying the model. I bought a bag of lead shot form a sporting goods store. It was in the reloading supplies section of the store. The bag contained enough lead shot to fill 2, 3 pound coffee cans. I think I paid $20.00 for the bag of shot, and ended up selling 1/2 of it to another model railroader for $10.00 or whatever 1/2 of my price was. They also used to sell lead sheet at the local hobby shop for adding weight, but I don't know if that is still available. If you can get lead sheet, it can be formed to fit tightly into the top of hoods or cab roofs and glued in so that it completely disappear if painted to match the cab.

[Green_Elite_Cab]

I was going to suggest changing your weights, but Dr Wayne already covered my suggestion. Most locomotives have removable weights installed from the manufacturer, but by replacing the steel or zamac factory cast weights with lead, you can add significant amounts of weight without modifying the model. I bought a bag of lead shot form a sporting goods store. It was in the reloading supplies section of the store. The bag contained enough lead shot to fill 2, 3 pound coffee cans. I think I paid $20.00 for the bag of shot, and ended up selling 1/2 of it to another model railroader for $10.00 or whatever 1/2 of my price was. They also used to sell lead sheet at the local hobby shop for adding weight, but I don't know if that is still available. If you can get lead sheet, it can be formed to fit tightly into the top of hoods or cab roofs and glued in so that it completely disappear if painted to match the cab.

what is the thinnest sheet available, and how easy is it to cut?

[doctorwayne]

The sheet lead that I have is about .050" thick (a little thicker than 3/64"), but I'm sure that it's available in other thicknesses. You can cut it with tin snips, but a couple of passes with a utility knife works just as well, and will allow more precision if you're trying to fit it into a particular space. Make sure to thoroughly wash your hands after handling the lead, too.

Wayne

[Trolleyfan]

You can get lead putty from A-Line/Proto-Power as their item number 13010 but their website says it's out of stock right now (8/27/2009). Being a putty you can pack it into all sorts of nooks and crannies in the chassis and body. I used this on a project in HOn30 to add enough weight to a very small locomotive (critter to some) that I built from a Nigel Lawson etch kit of an O&K RL1c. The loco is just over an inch long, barely over 3/4 of an inch tall and just over 1/2 inch wide.

You can see some photos (not mine) and the actual dimensions of the loco here: http://www.nigellawton009.com/OandKRL1cMontania.html

[Green_Elite_Cab]

The sheet lead that I have is about .050" thick (a little thicker than 3/64"), but I'm sure that it's available in other thicknesses. You can cut it with tin snips, but a couple of passes with a utility knife works just as well, and will allow more precision if you're trying to fit it into a particular space. Make sure to thoroughly wash your hands after handling the lead, too.

Wayne

is lead significantly heavier than most common locomotive weights?

For example i have several atlas AEM7s, and anything the doesn't have a motor or cab interior has weights in it, but its not enough. there are several tight and oddball spaces where more weight could be put into (like a thin sliver under the roof and some chunks in the cab), but there are also two large weights that fit between the motor. If i could replace them with lead (and just cut it to size), would that increase the weight of my locomotives?

these things are good, but underpowered. I'm convinced its because of their size, and not their actual pulling power.

[Russ Bellinis]

I'm not sure exactly how heavy the material used for typical locomotive weights compares to lead, but I would guess somewhere in the neighborhood of twice as heavy.

[doctorwayne]

is lead significantly heavier than most common locomotive weights?

The densities of the three most commonly used materials for weights are as follows:

Zinc - 445lbs./cu.ft.
Zamac (a zinc alloy) - 407lbs./cu.ft.
Steel - 490lbs./cu.ft.

The density of lead is 709lbs./cu.ft.

Not only is the lead denser, it's also easier to work with: cutting, filing, casting, and malleating (beating into shape with a hammer) can be done with simple tools that most people would have on-hand.

Wayne

[Russ Bellinis]

Of course if you want some really impressive weight, you could use gold! I worked for Kaiser Steel at their Eagle Mountain Iron Mine back in the early 1970's. I had to go find another job when they closed down and laid off most employees during the long shoreman's strike on the West coast that lasted 6 months. Just before I retired I met a mechanic at one of our customer's shops who had previously worked at Eagle Mountain before they closed the mine completely as far as iron ore was concerned. He told me that there was a guy looking for gold on a claim next to Eagle Mtn's. West pit. Kaiser had been trying to buy his claim to expand the mine for years and finally the guy got discouraged and sold it to Kaiser. They set charges and blew off the side of the mountain. Typically they drilled to set the charges during the day, set the charges and blew them at dusk, and then loaded the truck to take the ore to the pelletizing plant at night. Once the ore went into the plant it would be crushed, iron separated from dirt, and compressed into what looked like rabbit pellets and loaded into ore cars for shipment to the steel mill in Fontana (where California Raceway is today). Nobody noticed until the ore had gone through the smelter and been formed into ingots that their fork lifts could not lift. When they checked on why the fork lift couldn't lift the ingots, they discovered that they had found gold! I don't know if the story is true or a legend, but it makes a good story anyway.

[nachoman]

Of course, you could use depleted uranium. too bad it is likely to make you sick over time.

[Green_Elite_Cab]

Of course if you want some really impressive weight, you could use gold! I worked for Kaiser Steel at their Eagle Mountain Iron Mine back in the early 1970's. I had to go find another job when they closed down and laid off most employees during the long shoreman's strike on the West coast that lasted 6 months. Just before I retired I met a mechanic at one of our customer's shops who had previously worked at Eagle Mountain before they closed the mine completely as far as iron ore was concerned. He told me that there was a guy looking for gold on a claim next to Eagle Mtn's. West pit. Kaiser had been trying to buy his claim to expand the mine for years and finally the guy got discouraged and sold it to Kaiser. They set charges and blew off the side of the mountain. Typically they drilled to set the charges during the day, set the charges and blew them at dusk, and then loaded the truck to take the ore to the pelletizing plant at night. Once the ore went into the plant it would be crushed, iron separated from dirt, and compressed into what looked like rabbit pellets and loaded into ore cars for shipment to the steel mill in Fontana (where California Raceway is today). Nobody noticed until the ore had gone through the smelter and been formed into ingots that their fork lifts could not lift. When they checked on why the fork lift couldn't lift the ingots, they discovered that they had found gold! I don't know if the story is true or a legend, but it makes a good story anyway.

definitely a good story, but as it turns out, lead is still heavier per volume than gold, by a difference of 10.27 atomic mass units. that might be the difference between atoms, but it adds up after a couple moles of the stuff!

Actually, i think i have a similar story. In either 1906 or 1907, there was a barge bringing lead to the National Lead corporation on the Arthur Kill, between Staten Island and New Jersey. they were going up river, when suddenly the barge (which was over-loaded) tipped over, and 2/3s of the lead ingots fell overboard. there was a scramble to recover the cargo, and during this operation, it was revealed that the operators of the barge had been smuggling silver in with the lead. they got a lot of the ingots, but they weren't able to get most of them.

flash forward about 60 years, two teenagers (at the time) my grand parents knew were searching the out-shoot of a dredge looking for arrowheads (they are all over Staten Island), when they found chunks of ingots torn up by the dredging blades. they took these ingots to a scrap dealer, who claimed it was lead and gave them a few bucks for it. years later they would learn they very well could have had silver, and the scrap dealer may have not been so honest with them.

you gotta do your research!