My K-27 (#455 with snow plow) and an Accucraft combine total about 65 inches.  That is coupler face to coupler face.

Chuck

Bob C:

Adding a bridge rectifier will convert the AC to DC.  My dad and I used a Lionel Transformer with a Bridge Rectifier for many years on an HO layout.  I have no idea what the effect of the rectifier has on the voltage and amp output.  It will work, but I don't know how well!  Which is why I suggested that he get a DC power supply.

Chuck

You will want between 10 and 18 volts.  The engine will draw about 1 amp.  Long trains, tight curves and grades will increase the amps.  Adding sound, smoke units and lighted cars quickly increase the power needed.

Most of us have and recommend power supplies that have minimum of up to 20 volts and 10 amps. 

Your Lionel transformer with a bridge rectifier should work, depending upon the power out put of the Lionel unit.  Their larger units should be OK, but if you have a smaller (starter) unit you will probably need to start over.

You would probably be better off to get a DC unit with power to spare.

Chuck

On my layout here in Virginia, my K-27 runs with out any problems on AristoCraft wide radius curves (10' diameter).  On my patio layout in Arizona, using the same type of track, I had to put a little gear grease on the inside of the outside rail. The engine squeaked as the drive wheels entered the curve.  Based upon my experiences with this engine, I wouldn't go any tighter than 10' diameter curves.  It will probably run through 8' diameter curves, but there will be excessive wear and tear on the motor, drivers, and the track.

If you are planning an inside layout and the curves are too tight you will have black dust that drifts down from the track.  This is very fine pieces of brass that is being ground off the inside of the outside rail.  Sooner or later you will have to replace some or all of your curved track.  Engines with a shorter wheel base like the Bachmann Connie, Annie or the LGB mogul might be better suited to curves less than 10' in diameter.

Chuck

LGB made electric switch throws that can be controlled with a magnet on the bottom of the engine.  Their system is called EPL. 

If you are running track power you have another more serious problem.  If you are returning the train back on the same track after going around the shed, you have a dead short.  Follow your wiring around the track.  You will quickly discover that if the positive rail is on the outside , next to the fence it then is on the inside after going around the shed.  There are kits on the market that can be used to change the polarity of the track when the train is in the reversing loop.  LGB made one and if you are handy with electrons, you can build one.

My recommendation is to add a second main line parallel to the one next to the fence for the return trip.  In the long run it will be a much easier solution and you won't need to worry about automatic switch throws. 

If you are running battery power you can forget any problems with reversing loops.

Chuck

I think the "11VA" is the number that you start with.  That is the highest number you will get if you multiply the volts coming out by the amps being used.  For your power supply Volts X Amps = 11.  So if you are runnint at 11 volts the unit can handle a 1 amp load.  If the voltage output is 1 volt it will handle 11 amps.  The higher the VA the better the power supply.

At the full 17 volts out put you will have 11/17ths of an amp.  Barely enough for a one motor engine let alone a smoke generator and a car with lights.

Most of us use 10amp or higher power supplies.  Your new 2 amper won't run much at all.  It will overheat and cut out frequently.  I have 2 10 amp power supplies and one 15 amp.

If you have 300 feet of track you are most likely to be running long trains with larger engines having more than one motor.  When planning your power needs figure on one amp per motor.  For most engine motors that is a little on the high side, but it is better to have more power than not enough.

Lighted cars will also add to the current draw.
Chuck

One other thing that I should have mentioned is the width of the opening into the covered bridge.  My Bachmann Shay (1:20.3) is about 4.75" wide while my LGB mogul (1:22.5/24 (?))is 4.25" wide. 

If you have a curve leading into the bridge you will need an opening even wider than 5" to take care of the overhang of the engines and cars.  The opening should be at least 5.25" wide if not wider.  I would probably go with 5.5 or 6" just to be on the safe side, if the track is straight coming into and out of the bridge.  If it is curved you will have to experiment to see how much overhang you have.

I have read comments from people on the "mylargescale.com" forum that they had to redo all their clearances and abutments when they went from 1:22.5/24 to 1:20.3.

I had to move some rocks near the track back when I started running my USAt streamliners. The center of the car was hitting the rocks, because of the length of these cars caused under hang on the inside of the curves to scrape the rocks.  I am using Aristocraft 5' radius curves.

Chuck

Most of the manufacturers of Large Scale engines suggest a maximum of 22-24 VDC.  Some manufacturers (Bachmann, USAt, and AristoCraft) engines would fly of the curves if they were run at 24v. Those give good performance at 12-15v.  LGB on the other hand needs higher voltages in order to obtain a reasonable speed (15-20v).  Their Mallets seem to require 20-24 volts. 

Accucraft because of the low gearing appears to me to require higher voltages (20-24v).  My Accucraft K-27 seems to crawl at 22v (track power) and my K-28 isn't very fast with a 19.2 battery pack.  Flat out at full power they both run at prototypical speeds with the max a little less than 30mph (scale speed) 

It all depends upon the engine, the track (radius of curves and grades), and load (length of train).  The one constant is NEVER go over 24 volts.  If you are buying a power supply get one that maxes out at 24v.  If you are going battery, you probably don't need a 24 volt pack..  I am using battery packs that put out about 19v and that seems adequate.

Chuck

Measure the height of your boxes.  Open up the box with the tallest height.  In all likely hood that will have the tallest engine.

My guess is that the Shay's are the tallest.  The Shay box I have is a little under 11 inches tall and the engine is about 8".  My Shay came with three different stacks.  With the short stack I'm using the highest part is the "brass" fixtures on the top of the steam dome.

I would add a minimum of an inch to the highest engine.  This would most likely give you enough clearance for any future engines.

Chuck

PS: I wouldn't trust anyone to make these measurements for me. 

Before you install it, find out the maximum voltage and amperage that the controller can handle.  On most HO/N engines the maximum voltage is around 12 volts.  Many "G" engines barely run at 12 volts and usually max out at 20 to 22 volts. 

Typical "G" engines draw more than 0.5 amps. 

You need to know if Thomas will burn out your controller.

As to your original question, I think that if you set it to NMRA, as that is the conventional standard, it should be OK.

Chuck

Kevn:

I have to agree, but once they get back on the straight they look fine.

Seriously though, over the last 15 years my new engines have out grown my layout.

I just close my eyes when they enter and leave the curves (5' radius).  

When I built my layout in 1994, that was the largest sectional curves available.  It is either rebuild the whole D**n thing or just say it's my railroad and I'll live with it.  I always recommend that when someone is starting out that they use the largest diameter (radius) curves that they can fit into the available space.  

And it is only on entering and exiting a curve that they look odd.  Once in the curve the visual problem disappears, sort of.

For me 10' diameter was a major step  forward.  My layout in Denver had two loops, one with LGB 1500 series curves (2.5' radius) and the other had LGB 1600 series curves (4' radius).  That doesn't include my cog train with LGB 1100 curves (2' radius).  

Fortunately back then the engines and cars were all shorter.

Chuck

Check the following places:  in the cab on floor, or backhead of the fire box, under the cab, or in the tender (remove the coal/wood load).  Bachmann and other manufacturers have hidden switches in many different places.  Since it is a Spectrum engine I would be surprised if there isn't a switch somewhere.

Thomas and Percy in the sets, run opposite to the Large Scale (LGB) convention.  They are set for the NMRA standard.  Percy bought separately has a polarity switch and so does James.

Chuck

At the risk of being told that I am the south end of a north bound horse, I'll say that there is no Spectrum 10-wheeler.  The Annie is just a version of the 10-wheeler.

Chuck

Without the engine on the track put each car on the track and check each car for a short.  Start with the tender and work your way through the train.  It is possible that one of the trucks is wired backward creating a short, or a truck got turned around.

I think that the passenger cars are lighted, so there could be a short in one of them.

Chuck

Several suggestions:

As I recall I had similar problems with them on LGB 4' diameter track, but did not with larger diameter track.  When I commented on that problem, someone said that they didn't have any problems with the Bachmann track that came with the set.

First, try adding some weight to the cars.  They are very light and some weight should help keep them on the track.  Try a can or two of tuna fish or something of similar weight.

Second, the hook and loop couplers on Anne and Clarabel are fixed to the body of the car and do not rotate as most hook and loop couplers do when they are truck mounted.  Take a paper clip and use that to hold the two loops together.  That will extend the distance between the cars and should help them enter curves.

Chuck

note added 12-31-11

I had a relatively long discussion on mylargescale.com regarding Thomas and the cars.  If you read through it, especially some of the later posts you will read comments and solutions regarding the derailment of the cars.

http://www.mylargescale.com/Community/Forums/tabid/56/aff/17/aft/113445/afv/topic/afpgj/3/Default.aspx#138580

This link brings you into the third page of the thread.  you will need to click on the "1" on the right side of the page near the top in order to get to the start of the thread.