A beginner’s guide to designing trains

S02E02: Working out what kinds of carriage you need

As of last week, we’ve started a new series of articles looking at what goes on behind the scenes at Midnight Trains. After a previous season dedicated to the purchase of trains, Midnight Weekly is now in the midst of a five-part season laying out everything you need to know about designing trains (plus all the great stuff we’re doing to make sure the design helps reinvent the wheel when it comes to the sleeper-train experience).

In the first instalment, we told you all you need to know about ‘physical space inventories’: an essential step to work out what services you want to offer on board, depending on the target market and market position of the operator. This week, we’re progressing to the next stage: now we’re going to make sure that inventory fits within the limited space of the train, assuring both comfort and optimal use of square footage, in order to define the layout of the carriages (i.e. the two-dimensional place of the interiors of each type of carriage) and the composition of the trains (i.e. the number of each type of carriage).

A train made up of a locomotive and passenger cars is a space limited in two ways. Each carriage is generally 26.4 metres long and 2.8 metres wide. As for the full length of the train, it will generally be limited to 14 carriages (so each will be accessible from the platform (which is generally around 400 metres long). It is therefore necessary for us to fit everything we want as an operator within 14 carriages measuring 26.4 metres by 2.8 metres.

Let’s start by working out the number of different carriages we’re going to need to fit in the physical space inventory. As per last week, we’ll be using the example of a sleeper train with a luxury image targeting business travellers. Here are the four components of the space inventory:

  • Individual bedrooms with private showers
  • A dedicated, seated restaurant space
  • Soundproofed meeting rooms with good Wi-fi
  • A soundproofed conference room with good Wi-fi

One approach could consist of giving each space its own dedicated carriage. So we’d have four different types:

  • A carriage containing individual bedrooms with private showers
  • A restaurant-carriage
  • A carriage containing several meeting rooms
  • A carriage dedicated to conferences

Another, radically different approach would be to include all kinds of different spaces in a single carriage, which might make things a little more fun. In this case, we’d only have a single type of carriage which would contain:

  • A few private bedrooms
  • A restaurant area for those staying in these rooms
  • A couple of meeting rooms for those staying in these rooms
  • A conference room for those staying in these rooms

Travellers would then be able to access all on-board services in a single carriage.

This initial stage is pretty important: it will have a significant impact on the construction (or renovation) or the train carriages, and could dramatically change the time required and the costs. It could also have an effect on what the operator might envisage for the future. The higher the number of different carriages, the higher the cost and construction delays and the more likely they are to reduce flexibility in future operations.

When it comes to the delays and costs of construction, it should be noted that the manufacturer in charge of the layout of the train will face fixed costs for every stage of the chain of production. Every change that’s made to this chain will lead to new costs that can’t be cut and a whole new industrial set-up, engineers and materials. Moreover, each type of carriage will have to pass tests and receive official approval, which can be a long and costly process, which we’ve already spoken about in our previous series. So, the higher the number of different kinds of carriages, the higher the fixed costs for the manufacturer, with direct repercussions for the operator (especially if the order concerns only a small number of carriages).

Finally, working out how many different kinds of carriage you’ll need can also have an impact on the reserves required to run the service. This must be taken into account: it sometimes happens that a specific kind of carriage might be unavailable (due to technical problems or maintenance. Every operator must therefore buy reserve carriages to counter reduced capacity or other faults with the service.

If you follow the approach that allocates a different kind of carriage for each service (so four different carriages), the operator will have to have a reserve carriage for each type, that is four reserve carriages at a minimum. In the case where the operator has only a single type of carriage containing all on-board services, the operator could make do with only a single reserve carriage which could be used no matter which carriage is faulty or due repairs.

Now, as far as the flexibility of future operations is concerned, the maths is pretty simple. If an operator has only a single type of carriage, the trains will have much greater flexibility. In effect, could have anywhere between one and 14 carriages attached to the locomotive and still offer all on-board services. By contrast, if the operator had four separate kinds of carriage, you’d need a minimum of four carriages to ensure a full service on board.

So, with the same number of carriages at its disposal, the first operator could have several smaller trains running off to different destinations, while the second would be much more limited.

Let’s investigate a little more closely. Once you’ve defined the number of different carriages you’ll be using, and whichever approach you’re taking, you’ll then need to work out how exactly the carriages will be laid out, integrating all required modules before arriving at maximum capacity (in terms of the number of passengers, for example). This step will clearly require deep technical knowledge (both in engineering and industrial design) and comprehensive knowledge of railway infrastructure.

The industrial-design teams, along with the engineering teams, will then design a two-dimensional layout for each carriage that takes into account the dimensions of the carriage, various railway regulations (fire escapes, accessibility), other necessary infrastructure (corridors, electricity, placement of doors) and levels of comfort desired by the operator (minimum bed size, minimum width of corridors, minimum bag storage space, minimum bathroom size).

This process will give way to a diagram for each carriage and you can then proceed to the next stage: working out how many of each type of carriage you’ll include in the full service. If you’ve been following (we did promise we’d really take you behind the scenes), you’ll know that you’d be limited to 14 carriages – otherwise the train would be too long to fit on the platform.

If you take the example where you only had a single type of carriage, this stage would be pretty simple: the train would comprise 14 identical carriages. Easy. On the other hand, if you had several kinds of carriages, there are issues to sort out. You’d need to work out a configuration that will meet the requirements imposed by passenger capacity and the financial leeway of the operator.

Let’s suppose that the operator wishes to have a minimum capacity of 200 passengers on each train and that the diagram exercise suggests that each bedroom carriage would have a maximum capacity of 20. You’d then need at least ten carriages with bedrooms. The composition of the full train could then look something like this:

  • Ten carriages with bedrooms
  • Two restaurant-carriages
  • One carriage with meeting rooms
  • One carriage dedicated to conferences

So, how to optimise the quality of service and comfort within such a layout? This will be the subject of the following episode next week.

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