BUILDING A GARDEN RAILWAY

CHAPETER 12 : POWERING YOUR LAYOUT 

When it comes to anything to do with electrical power I am probably the least knowledgeable person to give advice. However, in the interests of providing a comprehensive guide to garden railways the subject cannot be avoided.

Whilst it is possible to circumvent the problem by dispensing with electrics and relying on live steam (or certainly radio control of battery powered locomotives- a subject matter in which I am equally intellectually challenged) you may still need to operate points and accessories or lighting circuits with some form of electrical current.

 Now it goes without saying that electricity is dangerous – especially when it comes into contact with water – and when it comes to the wet stuff this sceptre isle tends to experience more than its fair share of rainfall! Thus maintaining a healthy respect for the power of electricity is no bad thing when it comes to health and safety.

COMPLEXITIES OF DELIVERING POWER IN THE GARDEN

If electricity and water do not mix then how can we operate trains in the garden? The “secret” is to only install low voltage power in the unprotected environment and keep ll mains voltages (230v – 240v AC in the UK) safely indoors if at all possible. This is not to say that low voltage installations can prove a lot more difficult outdoors tha indoors.

Prior planning and the observance of electrical safety standards is critical to good operation but is frequently attempted as an afterthought at too late a stage using the “seat of the pants” methodology.

If you consider the added complexities of the task in hand:

        -        Routing wires in the garden environment usually involves burying the cables underground to avoid damage. This can prove quite labour intensive – especially if your             requirements change and everything has to be dug up and re-routed at some stage.

-       Large scale G Gauge locomotives draw far more current compared to smaller scale indoor equivalents: possibly as much as 3 – 4 amps where this is more than one      motor providing the pulling power

-       In general track runs tend to be much longer than on indoor layouts making it far more difficult to supply adequate power to the furthermost extremities of your line. The dreaded ‘ voltage drop’ is an every present danger..

-       In the garden train operators are in contact with the ground thereby making them more vulnerable / exposed / susceptible to death or injury from electrical discharges.

-       Even the connection of power to signals, points and buildings can prove more problematical (you cannot easily crawl under the layout board to fix things that go    wrong).

-       Garden train operators are directly in contact with the ground thereby making hem more vulnerable / exposed / susceptible to death or injury from electrical  discharges.

   -     Everything is exposed to the elements and a degree of protection is always advisable to mitigate not only the harmful effects of extreme weather but also wild life (you   would be amazed at the damage a mole can cause in a single night).

AVOIDING WIRING ALTOGETHER

I allude to this radical solution above and it is enlightening to see how many G Scale modellers who are averse to the use of electricity in the garden situation have adopted this stratagem and chosen alternative approaches. We will examine some of the more obvious methods below:

-       Convert to Battery Remote Control Operation

In the ‘ old days’ (when everything was in black and white as I tell my grand-children) reliance on battery power using non-rechargeable dry cell batteries was not always the most practical option. I recall running a Bachmann Battery Powered Baldwin 4-6-0 ATSF Steam Locomotive on six D Cells – they cost over £2 and lasted approximately 30 minutes!The advent of re-chargeable batteries went some way to changing the economics and feasibility of relying on batteries to power your locomotives but more recent developments in battery cell technology has revolutionised this approach.  Indeed the world of batteries is a fascinating subject and far too broad a topic to cover adequately in this guide. According to Wikipedia there are at least 39 different types of primary or non-rechargeable batteries and no less than 40 different types of secondary or re-chargeable batteries available. Faced with a veritable plethora of competing technological choices the following are probably the most popular at the moment or likely to become so in the future: 

  • Nickel–cadmium battery (NiCd)

Created as long ago as 1899 by in Sweden it using nickel oxide hydroxide and metallic cadmium as electrodes. As Cadmium is a toxic element and banned by the European Union in 2004. Nickel–cadmium batteries have been almost completely superseded by nickel–metal hydride (NiMH) batteries (see below). Nickel–metal hydride battery (NiMH)

First commercial types were available in 1989 and now a common consumer type battery which employs a hydrogen-absorbing alloy for the negative electrode instead of the dangerous cadmium.

  •  Lithium-ion battery (Li-oN)

The technology behind the lithium-ion battery is a relatively recent technology which is gaining ground as they are lighter, cheaper and smaller than other kinds of battery; don’t suffer from the ‘memory’ effect typical of nickel, lose less charge when not in use (and are sometimes supplied partially charged) and probably most important in this green age are easier to recycle.  However, there appear to be potential dangers in this technology due to the use of organic solvents prompting a move to a Lithium-ion Polymer Battery (see below)

  • Lithium-ion polymer (Li-Po) battery

These batteries are light in weight and can be made in any shape desired and are said to overcome the explosive characteristics of the organic Lithium-ion Battery but they lose their current more quickly and there may be other disadvantages. 

  • Lithium sulfur battery

A new battery chemistry which claims superior energy to weight than current lithium technologies on the market. Also lower material cost may help this product reach the mass market.

  •  Thin film battery (TFB)

A further refinement of lithium ion technology claiming a substantial increase in recharge cycles around 40,000 cycles. May have model railway applications.

  •  Smart battery

A smart battery has the voltage monitoring circuit built inside for specialist applications.

  • Carbon foam-based lead acid battery

A carbon foam-based lead acid battery with large energy and high power density combined with very long life.

  •  Potassium-ion battery

A rechargeable battery which can deliver remarkable cycleability, in the order of a million cycles, due to the extraordinary electrochemical stability of potassium materials

  • Sodium-ion battery

This type is suitable for stationary storage and competes with lead–acid batteries. A long and stable lifetime achieves very low total cost ownership. The number of cycles is above 5000 and the battery does not suffer damage by deep discharge.

  • Quantum Battery (oxide semiconductor)

A very small, lightweight battery cell with a multi-layer film structure, high energy density and high power density. It is incombustible, has no electrolytes, and generates a low amount of heat during its charge cycle, making it a very safe and long-lasting battery 

Recent Developments in Battery Technology

In recent months a new type of battery has been developed that could revolutionise the way we power consumer electronics and mirror the advances made in the miniaturisation of electronics. Apparently use of 3D-electrodes allows the creation of "microbatteries" that are many times smaller than commercially available options or the same size and many times more powerful. They can be recharged 1,000 times faster than competing technology such as lithium ion (Li-on) and nickel metal hydride (NiMH) equivalents. The scientific ' "breakthrough" involved finding a new way to integrate the anode and cathode at the microscale level.

This could pave the way for batteries that are 10 times smaller or 10 times more powerful enabling you to start a car with the battery cell from your cell phone.

It would seem that this technology could readily be adopted in large scale modelling in the future.

 Smaller and more powerful cells are easier to accommodate within the space available and last a lot longer. The parallel emergence of cheaper and more reliable radio control equipment has accelerated the adoption of this solution although the range of suitable locomotives has not really kept pace with the trend and it is still necessary to modify purchases to battery power.

 


BUILDING A GARDEN RAILWAY

CHAPETER 12 : POWERING YOUR LAYOUT 

When it comes to anything to do with electrical power I am probably the least knowledgeable person to give advice. However, in the interests of providing a comprehensive guide to garden railways the subject cannot be avoided.

Whilst it is possible to circumvent the problem by dispensing with electrics and relying on live steam (or certainly radio control of battery powered locomotives- a subject matter in which I am equally intellectually challenged) you may still need to operate points and accessories or lighting circuits with some form of electrical current.

 Now it goes without saying that electricity is dangerous – especially when it comes into contact with water – and when it comes to the wet stuff this sceptre isle tends to experience more than its fair share of rainfall! Thus maintaining a healthy respect for the power of electricity is no bad thing when it comes to health and safety.