Electrification and modeling

Electrification and modeling

 

By Ernest H. Robl

 

In a previous installment, we looked at why most European railroad main lines are electrified.  This time around, we’ll look at what implications this has for the modeler of European railroads.

If you model contemporary European railroading – in fact anything post WW II – and you are trying to depict a heavy-duty mainline. That mainline will need catenary.

Yes, there are still some non-electrified branch lines, but, particularly if you want to include modern high-speed trains among your rolling stock, you cannot do this without catenary.

 

Good news, bad news

 

The good news is that in scales N through G, catenary is available from a variety of manufacturers, and, particularly for HO, you have quite a few manufacturers to select from.

The bad news is that, for catenary to be reasonably realistic, it will take some effort in construction – more effort than is needed for basic track work.  And, to go with complex track work, the catenary will take commensurately more effort.

So, the best approach to electrifying your layout is to include consideration of catenary in early planning.  You can add catenary to an existing layout, but you will need to work around structures and other delicate items already on the layout.

 

Decisions

Two of the basic decisions you need to make are whether you actually want to power the catenary and whether you want to continue your catenary through hidden areas of the layout.

In the days before digital, catenary offered a means of operating more than one train on the same tracks, without having to resort to a lot of complex wiring and dividing your layout into many electrical blocks, each of which can be switched on or off.

Today, digital controls take care of that, and catenary is mostly for show.  In fact, because with operating off live catenary you only have a single point of electrical contact (between the pantograph and the wire) this form of feeding current is not particularly suited for digital operation.  Momentary loss of perfect contact is not much of a problem with analog operation, but it can cause problems for a reliable digital signal. In digital operation, this would lead to flickering of your locomotive headlights and any internal lighting for coaches. It could even result in train stoppage.

With digital power through two rails, you have current pickup from as many as four wheels on each side of the locomotive.

The question of whether to continue your catenary through hidden parts of the layout – now that you’ve decided you’re not actually powering locomotives off the catenary – depends on several factors.  If you have adequate clearance within those hidden sections and are sure that raised pantographs cannot snag on any obstructions, such as feeder wires under the layout surface, you can do without catenary for the hidden sections.  This saves both time and effort – and a lot of money.

In this case, you simply need to continue the catenary for a short distance into your tunnel.  At that point, the catenary gradually rises away from the top of the track so that the raised pantograph of an approaching locomotive will gradually come into contact with the catenary.

However, if you run trains at high speeds, typical of modern high-speed lines or even major mainlines, even the point where the pantograph first makes contact with the catenary could be a problem.  Toward that end, several of the catenary manufacturers offer simplified “tunnel catenary.”  This catenary doesn’t have to look realistic, but does keep the pantograph in continuous contact.

 

Getting started

 

Entire books have been written about how to construct model catenary. Obviously, we cannot cover all situations in this brief overview.  Each supplier’s catenary is put together slightly differently.  Yes, you can combine catenary from different manufacturers, once you have some experience. Undoubtedly, you will have to customize some pieces by cutting them to the right length.

Most of the catenary manufacturers offer starting packages that come with samples of the various pieces you will need, plus more detailed instructions.  In some cases, the starting packages include an entire booklet on how to assemble this particular manufacturer’s catenary.  In other cases, a booklet is available separately.  By all means, invest in those instructional booklets.

But even before you purchases the first pieces, be aware that there are differences in the “style” of catenary used in various countries and during various eras. The biggest difference is the material and form of the masts and the construction (in the prototype) of the outriggers that attach to the mast to hold the catenary.  So, select a start package that mirrors the country and era you are modeling.

Note that on electrified spur tracks to larger industries, the catenary may deviate somewhat from the national standards, if the catenary is maintained by the industry and not the national rail system.

 

More considerations

 

Before we consider a few aspects of operation on electrified lines, here a few more important points.

 

  • By far the biggest mistake most modelers make is not keeping catenary masts vertical on inclines.  In the prototype, the masts are always vertical, regardless of the slope of the track.  Keeping the masts vertical, may require some modification of the base of the masts, filing them at an angle, for example.

 

  • On single track lines set in hilly or mountainous terrain, the masts are always on the uphill side of the track. The ground there is more stable.

 

  • On double track lines, the masts are normally on the outside of the track. Having a single mast between the tracks with two outriggers is normally only found in station areas, where trains operate at slower speeds, or light rail transit systems.

 

  • On straight track, the catenary is laid out in a zigzag pattern going slightly toward either side of the centerline of the track.  This distributes the wear on the wiper or palette part of the pantograph.  That’s why manufacturers of model catenary offer masts with both, long and short outriggers.  You need to alternate these to get the zigzag pattern.

 

  • Prototype catenary has all sorts of additional equipment for tensioning wires and managing the feed of electricity.  You do not absolutely need these items for your model catenary, but adding at least a few of them, such as mast-mounted small transformers, will add to the realistic impression of your catenary.

 

Tedium and challenge

 

In stations where you have many parallel tracks, you will typically have the catenary suspended from cross-spans supported by taller and heavier masts to the outside of the tracks.  Again, the style of these cross spans varies slightly by railroad and era. This is some of the most tedious catenary to assemble and should be done before you install other structures.

By all means, look carefully at images of prototype catenary. You cannot miss in most photos of contemporary European railroading, showing how things are done in the prototype.

By far the most challenging piece of catenary construction is the so-called spider web over a turntable.  In many cases, roundhouses built in the steam era, are now used to store and service electric locomotives.  For that, you need wires over each of the feeder tracks and going into the roundhouse stalls. There are some kits for these, but you can also make your own with stiff wire and some bending and soldering.

 

Operational considerations

 

To realistically model operations on electrified lines, you also need to be aware of some prototype practices on those lines.

Most electric locomotives, except smaller electric switchers, have at least two pantographs. Some engines, designed for use in multiple countries with different catenary standards, may have more pantographs.

The normal practice, with some exceptions, which we will get to in a moment, is to operate with the trailing pantograph raised. The reason for this is that if the operating pantograph is damaged by snagging on a defective piece of catenary or other obstructions, such as branches and other debris blown on the catenary during s storm, the locomotive will still have another pantograph to get itself home.  If the loco were to operate with its lead pantograph up also, debris from the snagged front pantograph could also damage the second pantograph.

When two electric locomotives operate together or in tandem, either double-headed with two engineers or two locomotives controlled by the same engineer, the usual practice is to have the front pantograph of the first loco and the second pantograph of the second loco raised.  This maximizes the distance between the contact points of the two pantographs and minimizes the effect of any oscillations in the wire caused by the first pantograph on the contact by the second pantograph.

Another exception is for a “sensitive” car behind the loco. This could be either an open-top auto carrier, rare these days, or a car with top windows, such as one of Swiss Panorama Cars.  In that case, the loco will run with only its front pantograph raised to minimize the soot from the wire hitting the first car.

On modern locomotives, the pantographs are actually individually controlled. It is theoretically possible for a loco to operate with both pantographs raised.  However, this is extremely rare and would only be used in situations were severe icing on the catenary causes problems with having effective contact between the catenary and the pantograph.

Although the spider webs over turntables are designed so that a locomotive can pass through with its pantograph raised the entire time, the normal prototype practice is for the locomotive to enter the turntable with its rear pantograph raised. It then drops its pantograph as it is turned to the appropriate track. It leaves the loco with the front pantograph raised, thereby never having a pantograph pass through the central hub, where the possibility of snagging is the greatest.  Of course, only very few digital locomotives have control of pantographs, so, for the most part, your spider web will have to be well constructed.

If you’ve been around stations where electric locomotives couple up to trains, you will see the locomotive couple up and then drop its pantograph, even if it doesn’t need to switch pantographs.  This is a visible sign to the ground personnel that it is safe to go between the cars and connect the head-end (“hotel”) power cable that feeds the lighting and heating on the passenger cars.

 

Finally, a memory

 

Finally, a memory of something that could happen only on an electrified line:

In the 1980s I had permission to ride on an electric locomotive on the busy double-track Austrian Westbahn line (Vienna-Salzburg-Innsbruck). I ended up riding with a well-liked veteran locomotive engineer who was making his very last run before retiring.

All the locomotive engineers on opposing trains – we met an opposing train on double track every few minutes – knew who was driving our train and that it was his last run.

As each train approached, each locomotive momentarily dipped its pantograph in salute.

I was told later that this was a very high honor, rendered rarely, usually only to trains carrying the Austrian head of state.

 

###ehr###

2 Responses to Electrification and modeling

  1. James R says:

    A Brilliant tale

  2. Jeff says:

    The current fleet plan does’t make a lot of sense. Scrapping the ALRV’s beofre the routes using these cars are actually converted to low-floor operation would push the CLRV requirements in the short term. Based on the data provided in the spreadsheet, converting Spadina, Harbourfront, Bathurst and roughly half of Dundas in 2014 would free up about 44 CLRV’s, of which 14 would be scrapped leaving only 30 cars to fill in for 42 ALRV’s to be retired the same year. Service planning at its best.Even assuming the CLRV retirements are postponed (leaving the full CLRV fleet available for service until at least 2015), this doesn’t make sense, unless they plan to in initially replace the ALRV’s on Queen with CLRV’s on a roughly 1:1 ratio, with a significant decrease in capacity. Which of course cannot be done. I get the feeling these plans are made up as they go along. Steve: I agree and think that whoever put together the various iterations of the fleet plan doesn’t know what they are doing. An ad hoc plan that looks good on paper as long as you know nothing about the actual effects.I was comparing the fleet plan from two years ago () and there are significant differences both in timing of route conversions and the number of cars assigned to each route. Interestingly, Dundas and Carlton, the hardest hit routes in terms of headway under the current plan lost five cars each compared to the old plan. Most likely they will change their plans again next year, so knows by how much the headways will actually change by the time the new fleet hits the streets.And speaking of headway, Steve, there is a small error in your headway calculation for the Queen route. If it uses 31 cars on a 5’10 headway at the moment, and the plan is to have 33 new cars once it is converted, the headway cannot increase to 5’30 , but will actually go down to about 4’51 , assuming no change in running times.Steve: You are correct. Because Queen is an ALRV route, the calculation for that line is different from the others in the spreadsheet and I had the fraction upside down. The correct LFLRV headway is 4:51 as you say. I will update the article and the linked file. Thanks for catching this.And one other thing that leaps right off the page: how come the new fleet, supposedly much more reliable than the current equipment, needs a 20% spare ratio, no better than the 30+ years old fleet it is replacing?Steve: In the short term, I could understand a high spare ratio as the fleet builds up and teething problems are dealt with, but that should not last forever and a lower spare factor should be possible later in the plan. On the bright side, this gives some headroom to put back those missing cars on Dundas and Carlton.

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