Merlin Monarch
Richard Finlayson, Steam in the Garden On-line Editor
10/15/95
(Written 4/93)
The photo and description of the Frank S. in the LGB catalog was the 2x4 over my head that made me realize that there were people in this world running trains in the garden on REAL steam. I had seen Aster ads in Garden Railways magazine, but I guess I never got past the price tags to figure out that there was something else happening there. When the lights finally came on I had visions of oily mechanical moving parts, and visions of HUGE plumes of steam! I put the acquisition of a life-time supply of Rail Zip on hold, ordered Marc's live steam exposé, subscribed to SitG, wrote a pleading request for information to Ron, and never looked back.
The last three years have been great; the oily bits and moving parts I have plenty, but that huge plume has been a little bit more elusive. Mamods (who would have believed it) yield nicer plumes, as do most externally fired pot-boilered locomotives, but gas fired beasts tend to be light on stack exhaust. Nevertheless I have been terminally bitten by the live steam bug, with burned finger tips and steam oil on the kitchen ceiling to prove it. Furthermore, and contrary to my training as a transplant Californian, a cold, damp day has taken on a whole new appeal for me.
But things change. In the April/May 1992 issue of SitG, the late Grover Devine's South Pacific Coast railroad was featured prominently, and my world was shattered. (Also, check out the cover of Sept/Oct 1992 SitG. Wow.) Not only was the SPC an inspirational railroad, but Grover had an Americanized Merlin Mayflower that looked great and put any plume I had ever seen to shame. I went hunting for other Merlins and found Grover's SPC loco featured in Marc Horovitz's "Live Steam" video and also in the recent "Garden Railways: A Video Album". Shortly after that Grover Devine wrote an article that appeared in the Nov/Dec 1990 issue of Garden Railway describing an exhaust line modification that contributed to the beautiful plume that his modified Mayflower produced. It's too late to cut this story short, but the result was that I called Merlin in the U.K. (I was living in Japan then) and ordered my own Mayflower. I've still got that one, and have since been inspired by Grover Devine's SPC locomotive to "Americanize" a second Mayflower.
I think you would be immediately pleased if you were to happen upon a steamed up Mayflower. Right from the start you will notice that plume. There is plenty of power within the range of the throttle motion, and the Mayflower responds obediently to the frequent changes in direction and the slow speed of spotting flats or gondolas in a yard. Merlin has an interesting way of mounting the radio control receiver and antenna. The antenna is cut to length and then soldered to the underside of a massive brass dome. The dome is then insulated from the boiler with a thin plastic sheet. The result, at least on my pike in Tokyo and this electrically "noisy" environment here in Philadelphia, is that the Mayflower is virtually glitch free. Cutting the antenna and soldering it to a big chunk of metal isn't exactly good form in radio control circles, but you can't argue with the responsiveness and obedience that I observed. Not to be overlooked in the least, I think you'll find the Mayflower to be an exceptional value in the live steam market. The price, combined with classic good looks and solid running, result in a very satisfying locomotive in my opinion.
From the fireman's perspective, these two Mayflowers have respectable endurance. A run is equivalent to other gas fired British locomotives with which you may have experience. The R/C switch is located conveniently yet unobtrusively in the cab. From the mechanic's perspective these two Mayflowers are solidly constructed and only require the usual care and feeding of a small scale live steam locomotive. In the unusual circumstance where I needed a part (lost nut, banjo bolt) Merlin was extremely prompt in answering my call for small parts.
As with most clouds with silver linings, that nice plume doesn't come without a bit of tarnish. At the top of the list is the use of some steel bolts and parts in construction. For example, the steel crank pins rusted significantly on the long, dark, humid trip in the hull of a freighter from Tokyo to Philadelphia. A pin on the valve rod link that slides in the expansion link is made of steel, as are the wheels, which are painted black. Steel bolts are used in a some cases to hold down the R/C servos. If you maintain the locomotive this shouldn't be a problem, but I get frustrated at the slightest tinge of rust on those crank pins. I use WD40 on a Q-Tip to keep these parts treated, and then lubricate normally. This seems to work OK so far, but Merlin should consider a different material such as their competitors use.
The lubricator is positioned conveniently in the doorway and the drain is very accessible. However the plug on top of the lubricator is in a slightly awkward position and a wrench must be used to reach in to access the plug. I sawed a slot in the plug and I now use a screwdriver which has made the job much easier.
I've seen a gaggle of steamers, but I've never seen plastic gaskets used for steam line joints and boiler fittings such as Merlin uses. Imagine cutting gaskets out of a white plastic milk bottle and you'll have the concept mastered. They work well enough, but if you over tighten the connection it actually compromises the seal. I've found that it is best to throw away any gaskets that I remove, and replace them with new ones (supplied by Merlin) because they don't seem to reseat very well.. A fiber gasket is used on the lubricator drain, and one of my next projects is to go hunting for fiber gaskets in the size that I need to replace all the gaskets on my two Mayflowers.
The finish on the cab part of the locomotive is very professional and appears to be as durable and tough as you would expect among the field of locomotives offered on the market today. There was a bit of unevenness on a part of the black frame on one of my locomotives and it appears that it is the result of brushed on enamel. It is not unsightly and is hardly noticeable. In contrast, the red paint on the buffer beam of the second locomotive is not wearing well at all; a defect that Merlin readily agreed to remedy.
I mentioned that the radio control response was smooth and obedient. Merlin has managed to pack effective R/C into a tight space and side effect is that the receiver is visible hanging from the roof, blocking the top of the doorway. The colored tag on the crystal that indicates the channel is obtrusive, and once removed will keep from drawing your eye to the receiver. The battery bracket is a bit stiff but a little eyeballing and practice will reveal the method that gets the best result.
There are a few notes of interest that should be pointed out. First, there is an unused threaded tap on the boiler. The possibilities include a rigged-up whistle (there's an extra channel open on the R/C for the shop foreman in you), a clack valve, or a blowdown/filler tap. Also, tinkering with the timing might give you a slightly smoother running engine. They both ran fine out of the bubble pack, but if you have an extra couple of hours you can screw around with this and see what happens. I got this tip from Wendy Davies at Merlin: Put the loco up on blocks, get it up to pressure, and set it in motion. Then use a fingernail to impede the motion of just the piston valve in one direction and then the other. A very slight pressure to limit the stroke in either direction might reveal that a minor adjustment of the piston valve throw (using the adjustment threads on the piston valve) could smooth things up. Both of my Mayflowers arrived with no timing problems, but after I took one apart this technique helped me reset things to optimal settings.
A caveat on other Merlin locomotives: I've had the chance to run and work on two other Merlins, both of them 0-6-0 types with modified Walschaerts reversing. One of them I still own. In the context of my experience I need to note that these locomotives were not as trouble free nor easy to operate as the Mayflower and should be viewed as a different kind of beast with accompanying strengths and weaknesses. My only point is that you should not apply anything written in this article to any decisions you may be making about a different Merlin locomotive. (Incidentally, the Monarch was exactly the same locomotive as the Mayflower but with a different cab/tank design. It is no longer offered.) The Walschaerts locomotives are also in an entirely different price class than the Mayflower. Likewise, my comments only apply to Merlin Mayflowers produced with the last two years. Additionally, any used locomotive should be thoroughly evaluated by persons with experience in these things. Also, note Peter Jones' comments on this topic in the August/September 1991 issue of SitG.
I significantly modified my second Mayflower to create a more American aura and to add a whistle. The photos speak for themselves; either you'll like the approximation or you won't. In either case it was very easy to add the detail parts and build the wooden cab. I relocated the lubricator so that it was more accessible from the opening in the back of the cab and this was probably the most difficult part. The Mayflower is of simple enough design that it is easy to break it down for bashing. For instance, two bolts remove the smoke box and four other bolts remove the entire cab assembly. The steam fitting are easily accessible as are the reversing linkages. I've included a drawing indicating the setup that I used to add the whistle.
It was an easy task... except for creating a whistle that sounded good. The valve I used doesn't open too much on the 60 degree throw that the servo provides so I did some experimenting with diameters and lengths to get a sound that I liked that was loud enough but low enough, and not too "airy". I've included dimensions but you should use the tuning method indicated to get the pitch that suits you. I got off easy on the tender because I had one left over from a Hemmens Porter modification. I build a draw bar and plate for the locomotive and off she went. I'm the type of engineer that's been know to back into sidings at full speed in order to get couplers from various manufacturers to mate, and I can report that the tender is usually the last part of the train to derail in these fits of impatience.
The plume is gorgeous, the price is right, the look is classic, the bashing potential is enormous. Merlin locomotives has changed hands a few times and seen different management philosophies over the years. I held off on purchasing a Merlin locomotive due to uncertainty about the company, but I can affirm that I've enjoyed my two Mayflowers as much as any of the other British locomotives in the quiver, and they are a lot of fun to run. I had fun Americanizing and adding a whistle to the one Mayflower, and I'd love to hear from anybody who has ambitions for Americanizing a Mayflower or who has interest in Merlin locomotives.
*A FOOTNOTE: Grover's article describing a modification to increase the plume on Merlin locomotives appeared in the Nov/Dec 1990 issue of GR. I tried his modification, and several derivatives, and found that the "as shipped" configuration produced the best plume of anything I could come up with. The problem with gas fired boilers is that the exhaust enters the smokebox, which is being heated directly by the exhaust from the boiler flue. Those hot gasses interfere with a good plume. Check this yourself. Prop a gas fired locomotive up on blocks, get it up to steam, and set it running. At room temperature you'll be lucky to see any exhaust after initial priming has been remedied. Now turn off the gas jet but leave the locomotive running. As soon as the smoke box chamber cools (half a minute at most) you'll see a nice plume start to form. Merlin's solution is to run the exhaust line up the stack as far as is cosmetically reasonable, thus increasing the exhaust's chances of hitting cooler air. An experiment to demonstrate this is to attach a length of SILICON tubing to the end of the exhaust pipe and run it out the top of the stack a few centimeters. You'll find that you get a nice plume even at room temperatures. (Don't leave the tube in there very long! It will melt!) Another evidence of this "hot chamber" scenario is that pot-boilered locomotives exhaust the heat from the meths or gas flame to the universe above the boiler, with no heat from the flame entering the smokebox area. The cylinder exhaust from these pot-boilered locomotives enters the smokebox, which is much cooler because of the lack of a source of open flame, and the resulting plume is much better than with center flue boilers. A side effect is that the exhausted steam doesn't exit the exhaust line at high speeds so the plume tends to roll lazily out of the stack. In terms of Grover's modification, the drawing suggests that the exhaust line be pointed at the front of the smoke box at the same height as the hot gases exit the boiler flue. I suspect that Grover's locomotives may have had a much larger lubricator orifice and where therefore injecting more oil into the steam line. In that case, the hot oil would hit the hot surface of the smoke box, be blasted by the exhausting gases, and possibly burn. Burning oil would in fact create a most terrific plume, and if that was the case with his two locomotives then I continue to be eternally jealous. I tried these modifications with no success, but such is the search for the huge plume. All of this said, the Mayflower does produce a significantly larger plume than the other gas fired locomotives that I own, or have seen. I have my theories as to why, but none that I can defend as readily as those stated above. I invite critique of my logic so that we may all come closer to the perfect plume.