The Scottish Region Study Group took Alloa to Warley show the other weekend, and gladly I joined the team. All went well other than I suspect age, wear and tear getting to some of the toggle switches. Most issues we had were ‘operator error’:
Chas plays disinterested ‘bad cop’ to Dave Franks, who’s trying eagerly to talk his way out of the red card he’s been given. Two members of the public look on bemused…
Alloa is pretty good really. The fearsome looking main panel is mitigated by some basic colour coding (by route) with some basic electrical arrangements which mean the number of silly errors are reduced. Exhibitions are hard work, and however professionally you approach them fatigue does set in. People do distract you. And sometimes your mind just glazes over.
But over the weekend – and since then – I’ve given a bit of thought to the whole issue of how layouts are controlled. I’ve never seen a good control panel. There’s impressive size, impressive complexity, impressive craftsmanship. There’s computer control, DCC handsets and there’s working lever frames. But all seem to have pretty clunky ergonomics and sketchy indication of what’s going on out there on the layout.
So I thought, let’s have a think about the errors that occur, and what might be done to design them out or at least minimise their likelihood.
Whenever Culreoch goes back out (if…) then the layout’ll be unfamiliar to everyone involved. It’s all very well me knowing which switch I wired to which gizmo – but it needs to be clear to everyone else that will lift a controller. So this blog post doesn’t aim to preach, it’s to record my thoughts for later reference.
What do I need from a control system then?
- Clarity and simplicity for the user
- Ease of construction
- Ease of repair when the layout is on show
- reasonable cost
And how do most operating errors seem to occur, thinking back on previous shows?
- Conflicting moves
- Points incorrectly set (facing or trailing)
- Train runs into an electrically dead section
- Incorrect signalling for move
- Conflicting signals
- Signals not reset after train passes/departs etc.
There may be more, I can always add to it.
I’ve taken the view that the mimic panel is probably the best way to lay out the information and controls, and thought a little about how each numbered error might be minimised using only the control panel design:
Issues 1, 2, and 3 above ought to be made obvious by control panel illuminations. Perhaps rather than a single ‘dot’ of an LED to indicate what controller (if any) is powering a section, a frequent recurring indication ought to trace the route. Then it might be more obvious where power is set, and where it meets a dead or incorrectly set section. Similarly point routing might be usefully clarified by a traceable line of illumination – whether this is combined with or additional to the power indication is yet to be considered. I like the idea of the set route being brighter, other live sections being slightly duller, and isolated sections unlit. Issue 1 should be backed up by electrical isolation such that collisions are prevented.
The signalling issues 4-6 arguably are preventable by interlocking them with each other and/or with routes set. However I think this would add complexity and adds to the number of reasons the layout could grind to a halt. A better solution would be for an error indication to be displayed clearly.
So there’s the theory: operators will make fewer errors if a panel is clearly laid out and concisely provides all relevant information.
I’d offer a sketch but have yet to decide how a continuous run bit of Port Road ought to be operated – pretty fundamental!