Dungrange

Yes, but there are plenty who simply buy a locomotive for a depot style layout, for which a Class 66 would be required, but an MRA set would not. Then there are those who build relatively small inglenook style shunting layouts, for which a Class 66 could be an appropriate locomotive for shunting stock, but the layout probably won't have the space for a seven foot long indivisible set of wagons, as it would require a layout at least 15 foot long to simply transfer them from one siding to another. Apart from large club layouts or gardens railways, I struggle to see the market for an O Gauge set. I'd anticipate the demand for a Class 66 to be at least ten times the demand for a set of MRA wagons.

I've no idea, but given that Dave moved on from Dapol several years ago and Dapol have indicated that they are unlikely to re-run these in 00 due to costs having doubled over the last decade (ie they would have to charge £250 for a set in 00), I can't imagine they will be produced in 7 mm scale. Each set would be around seven foot long and probably cost something like £700. Are there enough interested 7 mm modellers to make that viable?

Although in this particular instance, if the volume of the sound when standing 4 foot away was adjusted to match what would be heard three quarters of a mile from the prototype, then the sound would actually be too quiet. However, I agree that there are some that stand four foot from the model and think it should sound the same as if they were standing four foot from the prototype!

In the absence of hydrogen fuel tanks on the roof, underfloor storage, where the current diesel tanks are on a diesel multiple unit, makes sense. However, I note that the article states "The 3-car Class 314 hydrogen train will store 80 kg of hydrogen, which is sufficient for its use as a demonstrator train. Doubling this amount for passenger use would require some hydrogen to be stored within the coaches". Ultimately there will be a trade off between range and loss of passenger space. I think the Concordia iLint stores 98 kg of hydrogen, so I'm not sure if there is a need for a significant increase in the quantity of hydrogen storage required to make the train usable, but that will obviously depend on where such trains are to be employed. In some parts of the UK, the 15x units that these would be intended to replace will be busier than others and some routes will present the opportunity for more frequent refuelling. That may lead to small batches of slightly differently specified hydrogen multiple units.

Are batteries not just exactly the same thing? With a battery, it is charged by passing current through the cells in one direction to charge it. When it is discharged, the flow of current is reversed so that it powers the train. Energy is either stored in the battery or stored in a hydrogen fuel cell. From an operating perspective, full electrification makes much more sense than either hydrogen or battery technologies, as the operating costs are lower. However, overhead electrification comes at a significant capital cost, particularly where bridges need to be raised to accommodate the overhead wire, so service frequency needs to be considered as part of the overall business case. There is also an issue with capacity. There will be a need to electrify thousands of kilometres of the rail network over the next two decades and its unlikely that the funding and resources are there to do it all at one. That therefore produces the need to prioritise. I agree. Neither battery technology or hydrogen technology are suitable for freight trains, as neither can provide the range or power necessary to transport thousands of tonnes of goods for several hundred kilometres. Decarbonisation of the rail freight sector is almost wholly dependent on overhead electrification, so all freight routes should be seen as the priority, with 'twigs' left for other technologies until such times as the electrification of all freight routes (and suitable diversions) is complete.

Battery technology is indeed being looked at on that service.

Since the early bird cut off for these wagons in 00 is tomorrow, I've decided to stop dithering and just place an order: Mullet, Parr and Super Tench. The latter are technically too modern for me, but they look really nice.

I think the common factor is that there will most likely be a reduction in passenger space on UK trains to accommodate hydrogen fuel cells. Hydrogen, at current pressures, takes up something like eight times as much space as a diesel fuel tank to get the same amount of energy, so the choice is really between introducing trains with a much shorter range (where hydrogen is stored in tanks of similar size to existing diesel tanks), or using up some of the passenger space to accommodate larger fuel tanks that will give a similar range to current diesel multiple units. Unfortunately, the smaller UK loading gauge means that the options for placing large hydrogen tanks on the roof, as per the Concordia iLint are probably limited. To be honest, I don't think any of the demonstrator trains will be the start of a significant production batch - they are effectively just proof of concept trains. The advantage of reusing an existing body-shell is that it is more environmentally friendly, than building from scratch, so when presenting to an audience, such as at COP26, it ticks the right boxes. However, in the longer term, I'd expect most of the production batches to be built from scratch.

I think that's the point: water evaporates and falls as rain pretty regularly. However, of the CO2 emitted into the atmosphere, 40 percent still remains after 100 years, 20 percent after 1,000 years, and 10 percent as long as 10,000 years later. Yes, water vapour is the most abundant Greenhouse Gas, but is converted to rain pretty quickly.

The article @JeremyC linked to above states: "The Breeze is a three-car unit that is a conversion of a redundant Class 321 EMU. It has two driving trailer coaches, which each have roof mounted fuel cells and interior hydrogen fuel tanks taking up a third of the coach space. The central motor coach has the traction motors and batteries. The unit will have between 148 and 168 standard class seats which is more than the two-car Class 15x DMUs that they will replace. Alstom’s Breeze has hydrogen stored inside the train behind the driver’s cab. These trains will be designated Class 600 HMUs and so, as far as numbering is concerned, they will be the first of the 6xx category of units, a new classification for alternatively powered traction. Following discussions with various potential customers for the Class 600 HMU, it is likely that the first deployment will be in the Tees Valley, where Northern Trains have selected the Class 600 HMU as its preferred solution for the operation of zero-emissions rolling stock. This would initially be a fleet of ten trains operating services to Bishop Auckland, Hartlepool, Saltburn and Whitby. Their deployment will be supported by the UK’s first hydrogen transport hub in Teeside. As part of this, it is proposed to build a hydrogen train maintenance facility on the former Lackenby Steelworks site. This will consist of a three-road maintenance shed, stabling for 16 units, train wash and CET facilities along with a hydrogen production and refuelling plant."

No. The electrolysis process converts water into Hydrogen and Oxygen. That gives us the Hydrogen 'fuel' used to power these trains. However, the trains combine that Hydrogen 'fuel' with Oxygen in the atmosphere to create water again. We will therefore end up with exactly the same amount of water in the North Sea irrespective of how the Hydrogen is formed. Rising sea levels are a consequence of melting glaciers in places such as Greenland, which is due to rising global temperatures, which come from increasing quantities of Greenhouse Gases in the atmosphere, a lot of which are produced from burning oil.

It will most likely have to produced locally to wherever hydrogen trains are running. The problem is that the boiling point of hydrogen (ie when it turns from a liquid to a gas) at atmospheric pressure is minus 252 Celsius. Therefore you either need to keep hydrogen very cold (so that it is in liquid form) or you need to have it under high pressure so that it takes up a lesser volume. I think the majority of hydrogen fuel cells are currently using pressures of around 350 bar (ie 350 times atmospheric pressure), but that increasing that to 700 bar should be feasible. The problem is that it's going to be difficult to transport large volumes of hydrogen significant distances, so it's more likely that it will be produced on site using electrolysis, so that the high pressure infrastructure for storage and fuelling is relatively local.

Correct. They will most likely end up on relatively long rural lines which have a relatively low service frequency, as that means that overhead electrification is unlikely to be a viable solution (due to the high capital cost of overhead electrification schemes). Shorter lines are more likely to be suitable for Battery Electric Multiple Units (BEMUs), but with BEMUs needing a recharge every 50 miles or so, they are not really suitable for the Far North lines hence the reason why HMUs seem to be most likely on that line. Correct, Alstom have been running their Concordia iLint units in several European countries including Germany, France, Sweden, Poland, Austria and the Netherlands, on either demonstration runs or in service.

Yes, the Hornby uncoupling ramp needs to go on straight track and you need to make sure that when the three or five wagons are against the buffer stop, the coupling at the other end (which will couple to the locomotive) is clear of the uncoupling ramp. If it's not, then you'll never be able to remove the wagons from the siding.

Has anyone fitted Hunt Elite Couplings to these wagons to replace the internal couplings between wagons? https://www.westhillwagonworks.co.uk/hunt-couplings-c-2/hunt-couplings-elite-oo-gauge-c-21/hunt-couplings-elite-coupling-pack-for-Dapol-mra-mrc-wagons-oo-gauge-p-171 I'm sure that they must be better than the Dapol coupling, but they look too far apart in the photograph on the West Hill Wagon Works website.

I think that is correct. I thought Peco always made their track in the UK.

What I'd really like to know, is where is the location of the place that shows in these non-adds? Is that what the Caymen islands looks like?

If you have the Lokommander II (https://train-o-matic.com/download/tom_lokommander_ii_en.pdf) then page 67 of the manual suggests that CVs 48 to 57 control the light intensity of outputs 1 - 10.

A couple of years ago, a gentleman came along to one of our club meetings. He had just bought or been given a train set for Christmas, which was basically an oval of track. Unfortunately, he was under the illusion that it was necessary to have an oval of track for the train to work, so he was rather confused by our end-to-end layouts. He wanted to know where the power went at the buffer stop and how we had managed to 'complete the circuit'. I had to explain to him that the electrical circuit starts at one of the outputs from the controller, with the electricity flowing along one wire (let's say a black one) to one of the rails (let's say the outside rail). It then flows through the pickups on one side of the locomotive, through the motor (which turns and makes the locomotive move), through the pickups on the other side of the locomotive to the other rail. It then flows back to the other output on the controller via another wire (let's say it's a red one). Thus there is no need for a layout to be a circle or oval (unless you want to run trains round and round in circles). What is important is that all sections of track are attached to both sides of the controller and that they are wired consistently (ie all droppers and bus wires on the outside rail are 'black' (or whatever colour you have chosen) and all droppers and bus wires on the inside are 'red' (or whatever colour you have chosen) otherwise you would get a short. As you have described it, the layout should work. When you say the power enters at 5 o'clock, I assume that this means that the output from your controller is connected to the track at this point: two wires, one to each rail. Between 5 o'clock and 6 o'clock, the rails should be live via the fish plates. If you have issues here, then it would be a problem with one of the fish plates not connecting properly. I'm also assuming that your bus wires start at the 5 o'clock position, so the path from your controller is effectively along your bus wires with the first connection to the track being at 5 o'clock. Between 5 o'clock and 12 o'clock, you should have power via either the fish plates or the bus wires. The bus wires are technically not required, but is good practise because it gives two paths via which the electricity can flow (ie via the fish plates or via the bus wires). That should make it more reliable. If I'm understanding your issue correctly, you can run a locomotive from the 6 o'clock position to the 12 o'clock position in an anticlockwise direction, but the locomotive will stop at 12 o'clock because there is no power at any point on the other board (ie between 12 o'clock and 6 o'clock if driving in an anticlockwise direction). That therefore implies that electricity is unable to flow through your bus wires that are connecting the two boards together. A few questions spring to mind: What sort of wire are you using for the bus - a solid core or multi-strand cable? Multi-strand wire is more flexible and would be all that I would recommend for a folding layout. If it is a solid core, it's possible that the copper wire inside the plastic sleeve has broken in the folding. That wouldn't be obvious by inspection, but continuity along the length of each bus wire could be tested with a multimeter. You've asked how the bus finishes, which prompts the question, how have you started it? The fact that you can drive a locomotive on one board doesn't mean that the bus wires under that board are carrying power, as you could just be relying on the fish plates. However, if you have droppers at say 5 o'clock, 3 o'clock and 1 o'clock then power should be getting to your bus via some of these connections, even if you do have a poor joint somewhere. When the locomotive stops at 12 o'clock, does it stop because there is no power on the other board (ie you can't drive it from say 11 o'clock to 9 o'clock) or does it stop because there is a short (which would be evident by some sparking when it gets to the join)? If that were the case, then it would imply that your bus wires cross over, so the wire to the outside rail on the one board is connected to the inside rail on the other and vice versa. As you've designed it, the bus is terminated by connecting it to the track at 7 o'clock. There is, as @Robert Stokes has said, no need for the bus to continue past the last set of droppers and could in fact be the last set of droppers. However, as @Nearholmer has said, you could also continue these back across the baseboard join to connect 7 o'clock and 5 o'clock. I could argue that is unnecessary, but it does build in further redundancy because it means that your left baseboard could get power from either the bus connection at 12 o'clock or the one at 6 o'clock, so if one connection is damaged, the layout should still work. However, what confuses me about you post is the 'where it's going wrong is after 7 o'clock'. What exactly is going wrong at 7 o'clock, since if there is no power on the left board, an anti-clockwise train should stop at 12 o'clock?

How does your 'perfectly logical mind' come to that conclusion?

Supplier.txt isn't a website, it's only a page on the Central London Area Group (CLAG) of the Scalefour Society that lists details of suppliers who may be of interest to 'finescale' modellers. The top of the page states that corrections and additions to the list of supplier details should be sent to Russ Elliot (russelliot @ nltworld.com). I know nothing about C&G Models of Darlington except I think I once bought something from them at an exhibition several years ago. Looking at Google Streetview, there appears to be a business with the same phone number as C&G Models on the corner of Parkgate and Borough Street in July 2009, called North Eastern Models, but it seems to have become a tearoom and coffee shop by the time the October 2012 image was taken, so I think I have to conclude that the Supplier.txt web page is perhaps not necessarily all that up to date.

The original post does ask for advice on a budget decoder, if the Laisdcc decoder is not suitable for controlling a 6 volt motor - hence the suggestion of Zimo as a better budget alternative. The issue is that there are two ways to reduce the apparent voltage that the motor 'sees'. The first is to adjust the duty cycle using CV5 (which is, as I understand it all you can do with the laisdcc decoder) such that it only gets a pulse of power for a maximum of say 50% of the time depending on the value of CV5. That is fine for a typical 12 volt motor as is fitted to most ready to run models, so if you find laisdcc decoders do what you need on new ready to run models, that is great. However, as I understand it, it is not ideal to be powering a 6 volt motor with pulses of power that are more than twice the motor's rated voltage. That is more likely to cause the CD motor that has been fitted to burn out. The best way to ensure longevity of the 6 volt motor is to reduce the amplitude of the signal to the motor, so that it gets pulses of 6 volts rather than pulses of say 14 volts (or whatever the DCC booster puts out). As I understand it, the laisdcc decoder does not have that functionality, hence the recommendation to spend a few pounds extra on a better budget decoder for locomotives fitted with 6 volt motors. As I understand it, the advantage of lowering the actual voltage to the motor is that it leaves more of the duty cycle to provide finer control of the locomotive. It therefore increases the longevity of the motor, reduces the maximum speed and provides smoother control. I don't think the laisdcc decoder can do that - changing CV5 to give the desired top speed and hoping that the motor doesn't burn out too quickly is the only choice. I don't have any laisdcc decoders or Zimo for that matter - just ESU.

I think the separate PSU would only be to supply power to the point motors. They would still pick up the signal from the DCC accessory bus. My understanding is that Voltage drop (V) = Current (I) x Resistance (R). That means that R = V / I and if you are noticing a 5 volt drop with a current of 0.3 Amps, then you have a resistance in your circuit of 16.7 Ohms. I would say that 22 AWG wire is a bit on the light side (my own layout will use 20 AWG for droppers and 13 AWG for the bus wire) but 22 AWG wire should have a resistance of about 55 Ohms per kilometre, so your resistance is what I would expect over 300 m of 22 AWG wire. I doubt you have that much wiring, so I think the issue must be a poor connection somewhere - a badly soldered joint or a screw connection, where contact with the wire is poor (eg only a limited number of strands are making contact with the screw connection). I think the approach that I would take would be to measure the voltage at various locations starting with the output from the booster (controller) - I'm assuming this will be about 22 volts. Then work away until you find a high resistance joint by identifying where the voltage first drops to circa 17 volts. If you have a multi-meter that measures resistance, then you could step round the wiring to try and identify a double digit resistance between track and bus, if the problem lies with one of your droppers.

Where would the reinforced versions be used?

I think the answer has to be the size of your fingers plus half the width of the stock that you run, plus a little bit. If you model in 00, then half the width of the stock is probably about 20 mm. My fingers are about 15 mm and if I allow an extra 5 mm, then I'd say 40 mm would be a minimum, but if you have large hands or less dexterity, then you may want a bit more. I'd probably aim for 50 mm (2") as a minimum in 00. Obviously if you model in O Gauge, then you will need a larger distance. I agree with the above - if in doubt, test before you commit to fixing the track.