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Coping with Couplers
Given the frequency of popular questions, such as, "Which couplers should I use?" and "How do I switch couplers?," I thought I'd put in my own $0.02.
As a warning, this article represents my opinions and experience on the subject, but by no means will every Z-head agree with what I've written here.
In this article:
Feel free to write me if you have any additions or corrections to this page. Click on any photo to see more detail.
What's the Difference?
Marklin "fish hook" couplers (shown left) are larger, and therefore more sturdy and forgiving than their MT counterparts.
While MT couplers are comprised of five parts (including the casing, spring, knuckle, lip, and trip pin - see picture), Marklin couplers are only made of two parts: the single piece hook, and the spring.
Marklin couplers require no adjustments, and require virtually no maintenance.
I have Marklin rolling stock that is over 25 years old, and the original couplers are still trouble-free.
The down side, of course, is the unrealistic appearance.
While I'm at it, I should also mention the Marklin drawbar, a permanent coupler designed to connect two F7 units. For more information, see this section of Making Your Own Wired Multi-Unit Locomotives. Aside from the more obvious differences, there's still the matter of their day-to-day operation to be considered. Aside from looking good, couplers have to do three things.
The only time I've seen Marklin couplers fail is when the train collides with a car at rest at too high of a speed.
Instead of coupling normally, the two hooks get caught in each other, a condition that must be manually rectified.
MT couplers don't seem to have this problem.
The solution, of course, is to s-l-o-w d-o-w-n.
Here, a Micro-Trains 50' boxcar with chassis-mounted couplers and a PennZee 3-bay hopper with truck-mounted couplers are about to mate on a curve. Since they are not aligned due to the different mountings, the automatic coupling will fail. Note that the alignment of couplers is more important than just their ability to couple automatically on a curve. When these two cars are coupled, they will exert excessive force against eachother when traveling around a curve, which can very easily derail these lightweight cars. Here's another example of this problem (a American Z Lines C44-9W and a PennZee hopper); notice when they're coupled, the coupler on the locomotive must bend substantially to stay coupled with the hopper.
The problem is due partly to the different coupler mounts, and partly to the inherent pitfalls of mounting couplers to the chassis.
While chassis-mounted couplers are more prototypical (i.e. like the real world), their mounting causes them to point outwards on a curve, away from the center of the track.
The tighter the curve, the further away from center they point.
It has been suggested that chassis-mounted couplers are better for operations and when going in reverse, although I haven't seen any difference between pushing cars with truck-mounted couplers and chassis-mounted couplers. Another solution that will reduce derailments, while retaining chassis-mounted couplers, is to add weight to the more troublesome cars. Two small lead weights, placed inside the boxcars, directly above the trucks, will help the cars stay on track; the downside is that your locomotives will be able to pull fewer cars. I, of course, invite any opinions on the subject.
Remote Uncoupling To uncouple two cars without manual intervention, you'll need to install a device specific to the coupler type:
Marklin A Marklin 8587 or 8597 uncoupling track section must be installed in any location you wish to uncouple cars with Marklin couplers, usually in a yard. Since they are electric solenoid mechanisms, they must be wired to a switch and a power source. To uncouple Marklin couplers, a train must be in motion over the uncoupler. Push and hold the button when the desired coupling is almost over the uncoupler, which will cause the uncoupler to rise about 1/8th-inch to mechanically trip the couplers, and the train will separate. The reliability of this procedure, in my experience, is about 80% (assuming ideal conditions). The down side is that Marklin uncouplers are expensive, ugly, and installation requires wiring.
Micro-Trains To uncouple MT couplers, the train must be stopped with the desired coupler directly over a permanent magnet installed under the tracks (such as MT #921). Briefly put the train in reverse, and then move it forward again. The magnet will cause the two magnetic trip pins to separate, which will release the knuckles. It's an absolutely ingenious mechanism, although good reliability requires careful selection and installation of magnets. The magnets must be the right type (the rare earth magnets I've tried don't work at all), and must be strong enough to uncouple the cars, yet small enough to be hidden under the track (see this for what I've done). The benefit is that magnets are much cheaper than Marklin uncoupling tracks, require no wiring of any kind, and are completely invisible once installed. If you have rolling stock with both MT and Marklin couplers, you'll most likely end up installing both types of uncouplers in your layout. I've installed magnets under my Marklin uncouplers so the single section of track serves double-duty; see Converting Turnouts to Under-table Drive for details. There are also tools designed especially for manually uncoupling two cars with MT couplers without removing either of them from the tracks, but I've never used one. A standard awl does the trick nicely, and works for Marklin couplers equally well. Lastly, there's the matter of manually removing cars from the tracks when they're coupled to other cars. When I lift a car with Marklin couplers, it usually doesn't give me a fight. However, lifting a car with MT couplers usually takes its neighbors with it.
Coupler Coping Tips If you're like most of us, and haven't already committed your collection to only one coupler type, you have a combination of cars and locomotives with Marklin couplers and MT couplers. You can either switch them all to the same type (see below), or find ways to cope. Here are some tips to help deal with differing couplers:
Changing Couplers on your Locomotives and Rolling Stock The procedure for changing couplers depends on the specific upgrade path you wish to take:
The photo to the right shows a Marklin 8880 on its head. This chassis is very common, used in many European diesel and electric locomotives as well all American diesels. To remove the old coupler, just bend back the plastic cover (gently), and pull out the old coupler and spring. Most other designs are similar, although some require more disassembly. The exceptions are the moving trucks on steam engine tenders - see the tips on rolling stock, below.
When the old coupler has been removed, install Micro-Trains 901 or 902 replacement couplers (medium or short shank, respectively), according to the overly-lengthy instructions included with the couplers.
The left-most boxcar has a truck-mounted coupler; the metal plate is removed by cutting the three plastic spots with an X-acto knife. The plate is re-attached by re-melting the plastic spots with a fine-tipped soldering iron. I shouldn't have to tell you to be careful not to permanently destroy the coupler housing here. The middle car is a three-axle passenger car with chassis-mounted couplers. The coupler housing design is actually very similar to the left-most car, except that the metal plate is on the top rather than on the bottom. Just pop the shell off the chassis, and then follow the procedure above.
Lastly, the right-most car (an 8610 gondola) has a chassis-mounted coupler held by a common single plastic weld.
Carefully cutting the red plastic with an X-acto knife will allow the body - and the coupler pin - to be lifted upwards, releasing the coupler.
Once the new coupler has been installed, just push the pin back in, and re-weld it with a soldering iron.
Obviously this can't practically be done more than once or twice without rendering the pin unusable.
PUTTING MICRO-TRAINS TRUCKS ON MARKLIN ROLLING STOCK
REPLACING COUPLERS ON MICRO-TRAINS LOCOMOTIVES AND ROLLING STOCK
Aftermarket Couplers and Trucks Here are the different kinds of couplers and trucks Micro-Trains makes. Except for the #901, #902, and #949, all of the trucks and couplers are interchangeable (that is, they all share the same mount).
First, determine if the coupler is attached to the chassis or the truck - see the second and third examples in this photo, respectively. Essentially, MT boxcars and flat cars have chassis-mounted couplers, and MT locomotives and tankers have truck-mounted couplers. PennZee hoppers have truck-mounted couplers, too. The Rogue GP38-2 has truck-mounted couplers, and the American Z Lines C44-9W has chassis-mounted couplers, although both use standard #903 couplers. If you have truck-mounted couplers, you may have to replace the entire truck, depending on what you need to do and what's available. If you want to save money, you could disassemble the coupler on the truck, although I really don't recommend it. Remove the old truck by pulling out the pin (held by a friction fit or a snap-fit) with a pair of needlenose pliers. Find the appropriate truck style listed above (#954, #955, #956), and install it in place. If you have chassis-mounted couplers, simply remove the screw that holds in the old coupler, and screw in the new one - the procedure is the same regardless of the coupler style (MT or MT Marklin-style).
Choosing a Truck Style
The criteria used to choose a style for any paritcular application is simply historical accuracy. (Thanks to Micro-Trains for some of the historical info.) Archbar Archbar trucks were common on early double-sheathed wood box cars, flat cars, and reefers, but were completely phased out by the end of the steam era (circa 1938).Bettendorf Bettendorf trucks were the most widely used during the first 50 years of this century, appearing on steel boxcars into the 70's wood boxcars into the 60's.Roller Bearing Roller bearing trucks started appearing in the 30's, and were required on all new cars starting in 1966 and rebuilt cars starting in 1970. By 1978, more than 70% of North American rolling stock was roller bearing equipped.Andrews A contemporary of both the Archbar and the Bettendorf trucks, its cast frame design was less prone to failure and allowed the use of expensive, serviceable journal boxes left-over from retired Archbar Trucks. The two main spotting features are the bolts that attach to the journal boxes and the tie-bars from the bottom of each journal box to the diagonal of the casting.
Most, if not all Micro-Trains boxcars come with Bettendorf trucks.
FR hoppers typically have Bettendorf trucks, and Pennzee hoppers typically have Roller Bearing trucks.
Alan Curtis Models' 48ft spine car uses Roller Bearing trucks (1 pair #956 for the ends, and 2 pair #953 for the pivots).
That about covers it! If you have any comments, additions, and corrections to this page, I welcome your email. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
