DCB

Not if Thomas is racing Gordon its not! When my son was small we spent hours playing with a double track oval about 4'6" X 3ft with Triang Transcon locos with lights, single ended diesels topping and tailing 4 coaches hurtling round at incredible sped. Double track is fun for kids, a single track with passing loop more operating fun for adults.

A bridge rectifier is a set of four diodes arranged so that the polarity of the output remains constant irrespective of the polarity of the input. This polarity reversal occurs 100 ish times per second on mains derived AC power supplies. I use Bridge rectifiers on DC inputs to operate LED carriage lighting which would otherwise only operate in one direction. Going back to the OP the voltage will be (0.7 volts?) less with a bridge rectifier than a single diode as there will be an additional diode in circuit so the CDU will charge faster but to a slightly lower maximum voltage My diagram hopefully explains the concept. Commercially available bridge rectifiers come in a variety of shapes and sizes and usually have + and - marked on the relevant output terminals.

Resistance controllers typically deliver a minimum setting voltage of 18/19 volts off load. Of the variable voltage variety the OnTrack. I measured it gave from 0 volts off load in the centre "Off" position progressively up through the 3-4 volt range where locos start to move to the maximum. H&M Safety Minor, variable Transformers, started around 2.5 volts My diode based beast starts at around 5 volts,I never actually measured it, as its for Hornby Dublo locos, but when overloaded it will trip a 1 amp breaker at minmum setting. Motor speed is related to voltage, more volts more speed other things being equal, conversely the more load you put on the loco or motor the more amps it draws, with a variable resistor as the VA remains constant the motor is only able to draw more amps by slowing down, With a variable voltage unit the motor draws more amps keeping the voltage and speed very nearly constant (less losses) by varying the amps and VA (Watts). Take my 28XX. it runs quite slowly on a Triang controller (Variable resistance) until it collides with the buffers which stop it dead. On the OnTrack running at the same slow speed when it hits the buffers the driving wheels barely slow as it sits there slipping its wheels. On the OnTrack It goes much the same plodding speed up a 1 in 50 with 20 wagons as it does back down yet can run at a scale 65 mph if required. On the Triang (for example the Duette is every bit as bad) it needs a high power setting to climb the bank and almost zero to descend, it has to be driven all the time and I like to just set the speed and sit back and watch Using voltage drop in another context on starting a typical Bachmann Pannier the OnTrack drops the voltage less than 1/2 (One half) volt from the off load value, The test was run the engine, isolate it check the Off Load volts, flip the isolator back on recheck the volts. The Triang drops it 15 (Fifteen) volts from off load. Both start the Bachmann pannier at 3.5 volts. Think of it like this, Volts = Speed Variable Voltage = the controller knob varies the Speed Variable Resistor = the controller knob varies the power.

Laptop PSUs (power bricks) have excellent internal protection both for overload and over-temperature situations. But my little Acer brick is 19 volt 3.4 amps, that overload protection protects the brick, it won't protect your 1 amp wiring, motors etc if you get a short or partial short Does the pictroller have overload protection? Most model transformers have a 1 amp nominal overload built in.

Garden railways? From personal experience In 00 I find as long as you have plenty of weight on the pick up wheels, like my old cast body 94XX on a Romford wheeled chassis, and the tracks are not ballasted running in the rain is just as good as in the dry but traction is reduced by about 20%.. OK forget it if you have all wheel pickup DCC ready RTR, they don't seem to have enough surface pressure on the wheel tyres so don't break through the water's surface tension. Ballast holds water which effectively shorts the rails. Traction tyres don't work when wet, and steel rail rusts to a very prototypical colour. I suppose for exhibitions you could build the layout and then spray everything with very well thinned gloss varnish or clear lacquer.

Measure your "12 volt " power packs output before you start selecting resistors, 18 volts off load is typical. It may well be if you wire enough of these lights to the power pack it will pull the voltage down to 9 volts anyway.

I can see great value in a database so two layouts are not inadvertently given the same name, but a list of modeled locations is potentially less useful. The availability of stock, the preferred timescale, before the wholesale track rationalisations of the 60s 70s or even before or after the WW2 increase in facilities after are probably the most important drivers in a choice of locations to model. Actually visiting a location to be modeled is not a bad idea, there was an exhibition layout called "Fossebridge" at one time which was Ok unless you know Fossebridge, Its actually in a deep twisting valley. 1 in 6 hills each side. The full size railway was never built, but the model simply could not have existed, the curves were too gentle! Actually it is a fantastic place to model as a what might have been with post grouping the GWR (or maybe LMS) Cheltenham -Oxford trains passing the very close to the old hotel, crossing the Foss way on a level crossing at the bottom of a 1 in 6 hill and curving sharply to follow the Coln Valley. The way the hobby is evolving is Layouts being made as replicas of other layouts, and maybe a data base would encourage this. I have some 1950s magazines and the layouts then had tremendous operating potential and the owners describe their operation, whereas 2017 exhibition layouts simply seem to look good...... Until something moves and spoils the illusion.

There were some passenger service reductions fairly quickly after the outbreak of war which released stock in addition to the reserve stock kept for excursions. The Dunkirk evacuations were improvised at short notice with more or less anything which could turn a wheel, but most troop movements were planned in advance. The difficulty for modelers is the stock used was unlikely to be the latest express stock but rather stock cascaded from first line service and this would be likely to be 20-40 years old so pre grouping eleptical roof rather than Clerestory and the only RTR I know of is the Hornby Gresleys, though the early LMS stuff looks the part. Gresleys were also used on the Ambulance trains but I understand these were Air braked to be compatible with Continental stock and hauled by B12 locos rather than the local company's locos. A special originating at Catterick with some well weathered Gresley stock ought to be reasonably convincing for anywhere from Plymouth to Dover, to Stranraer or Wick, but not with an LNER engine much more than 50 miles from the LNER. At least some Anglo Scottish sleeping car trains continued to run during the war, though not shown in the public timetable and "Service Personnel" only.

Ontrack and Morley deliver less than 1 volt off load. the voltage rises with the control knob. Take a controller and put a voltmeter across the output (off load). Crack the slider or knob to minimum speed and read the voltage. Most are 16-19 volts off load. OnTrack less than 1 volt. I will do a video of the OnTrack later. I guess Crosland does not have access to a Morley or OnTrack. they rely on a single Potentiometer to give speed and reverse control, the remote has only 3 wires.... Hammant and Morgan variable transformers don't have such a low minimum voltage, nor do Playcraft diode based control units or my home made versions, but all give silky smooth low speed running and with modern mechs very stable speed over a wide range of up and down gradients with no need to adjust the speed control. The downside is they don't start as well as PWM with old fashioned Triang type motors and you have to develop a delicate touch on the speed control.

I'm dubious about using Laptop PSUs for model railway purposes, doubts about overload protection, and the difference in use, laptops charge for an hour or so and then the PSU just supplies a few watts. Railways can draw a big chunk of an amp for extended periods. The Bachmann probably won't deliver much top speed but its probably worth trying, it should have a decent overload protection so shouldn't burn the shed down.

Really? What happens when you want to isolate the "Common" side of a siding, you have to run two wires to the switch, to an isolator switch and back or you get weird results. if you don't go common you can just run a wire from the panel to the isolated section and one wire to the track, on either side. Like I said wiring part of my layout Common Return was a mistake. This evening section switch 11 fed from the panel on the "Common" side was left on with Evening Star on it. and the loco stopped with a point against it, 10 minutes later a combination of point settings (electrofrog) reversed the polarity of the unswitched rail and while we were running trains on a different part of the layout the damn thing moved 2 inches to short the point out and stop most of the layout. Even with sections it took a good 10 minutes to find what was wrong, and even then it took a great deal of thinking to work out what had gone wrong.

Most controllers control Watts, VA a setting for instance say 1/2 maximum speed can provide 6 watts, 6VA, 6 volts 1 amp, uphill 12 volts 1/2 amp downhill. Slow up, fast down. Voltage control units vary the voltage, 1/2 speed shall we say 6 volts, 6 volts 1 amp up hill 12 VA 12 watts, 6 volts 0.1 amp 1.2 watts 1.2VA downhill so the speed stays very much more stable than the usual PWM or (especially) Resistance controls. The difference between the two is quite striking especially when recent Bachmann and Hornby locos are running on an undulating layout, like in my loft. On the other hand I don't get any slowing on the far side of the layout from the single power clip some 18 feet with a resistance controller, the slowing is gradient related as is the helter skelter rush down the other side. Check out a Morley or OnTrack controller. On the other hand every single fishplate has had to be replaced on the outside branch and many have bridging wires added and we have a program of drilling the 1/2" thick baseboards to fit droppers, as well as live frog polarity switches due to constant problems, greatly reduced by banning old X04 motored locos and using an N gauge 9 volt 1/2 amp controller instead of a 1 amp 12 volt unit.

At Gloucester Horton Road they demolished roof and two walls of the main shed building and stabled diesels over the remaining pits while keeping the smaller buildings. It only had a ramped coal stage so no need to demolish a cenotaph type coaler. The rest of the area seemed to become a derelict haven for weeds and rats and other urban wildlife. There may have been small fuel points but they were more likely to be the remaining rump of near derelict steam sheds than new build. Aberdeen has what looks like a fuel point just south of the station along with a carriage washer, I might be wrong. Inverness has extensive facilities around the old Steam repair works and a section of this would be a good subject for a model.

Wiring looks good, your separate returns for up and down lines will pay dividends later on, I made the mistake of using common return for all of one station area of a layout and the mental gymnastics required to understand resulting weird faults was challenging. Much easier when you can put isolators and switched feeds in either polarity rail. As a rule of thumb, The smaller each "Section" or "Power zone" the easier it is to locate a fault and the more time you spend playing trains and the less fault finding. Those wired fishplates look so ugly, how will you disguise the gap when there is no room to slide a dummy sleeper under? Check photo of the real station. Tracks are usually paired with [Edit] a "6ft" way between the tracks as in up and down lines on plain double track and a [Edit] "10ft" way between the pair of running lines and sidings loops or another pair of tracks. I didn't realise this until the layout was too far advanced to change it and it now annoys me. No reason you can't carve lumps off points to optimise track work. I cut off the end of tie bars and trim sleepers in addition to sawing lumps off the end of points to make the track flow and to avoid short filler pieces as far as possible. I really hate short filler tracks, they never stay flat and look horrible. The voltage drop thing is interesting, I'm starting to think the people with voltage drop problems need to get a decent controller. One which controls voltage. Not wattage.

I have been reading of the early 350 Hp diesel shunters running at 30 MPH during WW2 in WD service. When was the restriction on speed, 15mph? brought in. It does seem quite bizarre that anyone would have designed or ordered so many if the design speed was so low.

Thats 1970s or 80s surely. Isn't modern era 2000 on? In my book there's 1825-35 early days 1835-1895, Dark ages no one models 1895-1923 pre grouping. 1923 -1939,Grouping 1940-48.war 48-62,steam 62 -68 death steam yellow end diesels 68 -85 blue, 85 -2000 sectorisation 2000 on modern.

Its about making sure the driving axle always has weight on it as much as anything. Personally I would consider a double chassis with a heavy 0-2-2 chassis with as much weight as possible over the driving axle pivoting around the trailing axle and a separate 2-0-2 chassis taking the weight of the superstructure on leading and trailing axles. There is little reason why you can't use two 00 motors and power all the axles, could be quite fun. or use a model car differential to power both trailing and driving axles from the same motor, in fact with a heavily weighted trailing axle and lightly loaded driving axle this should be most realistic as furious wheelslip would rob power from the trailing axle so it would probably not move rather than the take off like a scalded cat mode most models adopt when slipping furiously. Contemporary reports suggest the gentle slipping of singles on starting was quite a feature and marked out skilled drivers from their unskilled colleagues.

A double track circle in set track would be fun, I had a double track oval, 1st and 2nd radius just over 3' X 4'6" or so for my son which was great fun back when he was small (6' 2" now) and something similar but with sidings outside should be possible. 8 X 2 might be a better option for a scenic layout. Dock, cramped BLT etc.

The wiring looks good apart from the second feed on the bottom layout which could cause shorts if live frog points were substituted for set track. Obviously the layouts need a shunting neck/ fiddle yard on the left hand end or you won't be able to shunt them so with the 7 feet layout and 3 ft fiddle you are looking at a 10 ft length The track layout isn't so good. Set track wastes space, especially width. Re drawing with streamline, especially the Y points will free up a lot of width. Loading / Unloading Sidings should ideally be paired. Unloading space, two sidings real close together "4 foot" ish then unloading space then two more and so on. Marshalling roads in marshalling yards where shunters trucks roam vary, many are at "6 ft" spacing to allow "Shunters" men with uncoupling poles/ brake sticks to run between lines of wagons to couple up and pin down brakes. This shunting "thing" on the full size was on of a number of scenarios. Often one goods per day called and shunted a set of sidings, on the GW this could have anything from 28XX 2-8-0 to a Pannier tank on it, but all hell broke loose for half an hour and then nothing for the rest of the day , quite often this was one train in one direction only. Marshalling yards with lots of parallel sidings like Acton Yard and Moreton Cutting served to break up trains from a number of originating points and reassemble them for a number of destinations, these could work 24/6 with sundays off. Shunters trucks were frequently used Some small yards, Bridgwater quay etc, had a small shunter fussing around on day shift moving small numbers of wagons around to be loaded or unloaded as required. These were quite rare, but very frequently modelled and the locos would be the small shunters, tiny 0-6-0 (1361) and 0-4-0 shunters rather than the big 2721 and 57XX panniers. Again Shunters trucks were used for the shunters to ride on and carry their tools spare coupling links etc Other goods depots had shunters on day shift mainly moving wagons from reception sidings to be loaded and unloaded, often in and out of the big goods sheds, the small GW Panniers, 850s and 2021 did this sort of work pre war and larger ones before diesel shunters took over. Sometimes wagons were left unloaded in yards when there was no back load and no immediate need for them elsewhere, customers were charged demurrage for any wagons they had not emptied in a reasonable time. On models the need to remove some wagons, leave others partly emptied (or loaded) and bring in others is not given much thought.

9 seems to be the standard "In line" pinion which I use taken from dead scalextric can motors in my scalextric parts box. 8 to 12 teeth pinions are available and you can buy packs one of each 8/9/10/11/12 teeth pinion on Ebay or from model shops. The "Sidewinder" motor pinions which are spur gear pairs rather than crown wheel and pinion do not mesh with Lima.

Another victim of inadequate overload protection? PWM controller?

If it is a hidden area with no point motors why not mount the switches on top of the baseboard, I had to add polarity switches to code 100 electrofrog turnouts in the outside branch terminus normally covered by the "Rabbit Hutch," as the weather was getting to the contact tags. As the baseboard was very thick solid timber I used surface mounted miniature micro switches, 5 for £1 from Ebay " AC 125V 1A SPDT Subminiature Micro Lever Switch 5 Pcs SY E1Q7 Q4L5 W3P4 " Held in place with track pins. Some people say you get what you pay for so I don't mind paying 20p each. Probably wouldn't survive long on DCC but they are nice and neat.

So what is the price? it looks around £ 100 for a foot rise. I know form bitter experience and a failed spiral that there are two big problems with spirals, one which can be addressed by the manufacturer is the twist on the road bed and hence track but there doesn't appear to be anything to hold the upper inner corner of the road bed down in this kit unless the track bed is pre formed with a twist. The other issue is gradients have to be measured from true horizontal and not from baseboard datum, a 1 in 50 spiral gradient sitting on a baseboard sloping at 1 in 100 will vary between 1 in 33 and 1 in 100 if my maths are right. UK spirals should climb on a right hand curve to give the climbing train the easier gradient and reduce the twist on the ascending track which will leave some long wheelbase steam locos running on 3 wheels on a 2nd radius curve. US and foreign types drive on the wrong side so their spirals should go t'other way.

Was this the latest RM? August 2017? Haven't seen it yet my wife is supposed to be getting one as I write. The HST with buffers cab could (and should?) have been made standard for all the later BR diesels, class 38 and 39 etc and retrobodged to things like the class 31s. Also the DVTs should have been this style so depots could keep a complete front end and swap them when the local nutter gets his Fiesta T boned on a level crossing. Free lance is the only way to keep one jump ahead of Heljan, Bachmann, Kernow etc and have something different on your layout. I am thinking of a freelance line, maybe Isle of Skye, with freelance locos based on actual locos but adapted, Initially an Adams Radial with side window cab, LSWR were flogging them off circa 1900 which is when my line would have been built, and the GW were trying to flog saddle tanks, ex Welsh 0-6-2Ts, Metros etc in the 20s and 30s, so a 2721 with side window cab would be feasible, and that Hornby Smoky Joe with a side window cab on an 0-6-0 chassis would look the part for shunting Kyleakin quay. I think there was one whole day in 1926 when it did not rain in Skye hence the preoccupation with cabs, oh and shorter chimneys for a 12' 9" loading gauge. Chuck in a few Hornby Clerestories and various 4 wheeled Clarrie and Annabel bodies assembled in pairs on bogies and at an exhibition even the most vocal rivet counter will probably give up and wander away.

B P were unlucky in that the LNER Garratts schemed out by Robinson post WW1 with essentially 2 X 04 chassis were cancelled and replaced with one 6 cylinder Gresley monster. That boiler on a pair of second hand ex ROD chassis could have transformed freight workings. and with RODs available at a knock down price could have done so very cost effectively saving one driver, as they would have needed at least two firemen... The ROD boilers could have then gone on to new 4-6-0 chassis a la B6 or 6' version of the Immingham and given the LNER some nice reliable simple cheap 4-6-0s instead of the B7s.... Which gives more might have been locos to build which Heljan, Oxford, Kernow won't announce just days after I get mine finished.