Expandable camping trailer.

Tents makes sense – a small package opens up to become a big thing. On that logic a caravan looks daft. Towing a big thing full of empty space – dooh. It is more sensible to have something that can be towed easily, still full of all your kit, and then be opened up on site at the press of a button. A full off-grid energy system built in would be the cherry on top and a satellite dish that gets the footie running straight away wouldn’t hurt either. And that brings us to the

Original Twist Camping trailer.

You know those tool boxes where the top parts push away to reveal the box underneath? Well this trailer is just a big one with wheels on. The door frames at each end support the roof and lift it just like a four poster car lift. You arrive on site, the roof lifts up, the sides pop out and the roof closes down on them to lock and stabilise. The links that control the movement of the sides are steadied with torsion bars and chain and sprocket ties so powering it all is quite simple. Just one electric motor to make it all open up. The drawing shows one half closed and the other open; in practice both sides deploy together. The roof lift easily copes with the weight of the solar panels, dish, awning etc.

The side pods can contain beds with lights and TV built in and/or a kitchen unit. The choice is yours.

A shower room can be fitted over the draw bar as a separate cubicle that is entered privately from the main living quarters.

This design could be scaled up or down. Here it starts as the size of an SUV, for easy storage and towing, but still sleeps up to 5 when you get there. A bigger version would be sensational when deployed; imagine rolling into the campsite and opening up straight away, the dish locks on, footie on, beers out, all in about 2 minutes. A caravan that’s 4 metres wide before any canvas extensions go out! Stand by for a crowd of onlookers.

Heating is by a truck cab mini heat pump or gas.

The generous PV array raises an interesting question. If your electric tow car also had panels on the roof there could be significant range extension when all the panels are combined. In the new electric era tow cars will need all the help they can get. Note that the PV still works when you get home so it makes a useful uninterruptible power supply for your house – unless you park in your garage of course.

So there’s the idea. Does it exist? No, not yet, but let me know if you would like to build it and I’ll let you know how all the links work.

Features

Fits in a normal garage

Easy to tow – only as wide and as high as a car

Aerodynamic for economical towing

Automatic opening out and closing in a minute or two

Almost doubles in size

Roof raises for full height interior

Comparable with the biggest caravans

Sleeps 4 – 5

1.5kW of solar panels (4x 380W)

2kW inverter runs 240V fridge, TV, microwave, kettle, tools, lawnmower etc.

Built in awning and cover

4^th solar panel folds out to make porch cover

Moulded in satellite dish recess on one roof, covered when stowed

The drawing is done to fit existing solar panels but they are already bigger and better with 400W panels a good fit. Imagine a matching moulded roof on your tow car with another 3 panels fitted. A fantastic look and 2.4KW in total which is over 3 horsepower. Quite possibly this combination might be more economical to tow than a car on its own!

Plug all that in when you get home and watch those heating bills crumble. At next winter’s projected prices that’s well over £1,000 worth every year. While turning over energy ideas consider that your electric tow car has the equivalent of four Tesla powerwall battery things built in so your trailer is not only a monstrous power house when on the move but also a major part of your domestic energy strategy too.

Vehicle to grid chargers are the next big thing. At the moment it’s all possible if your tow car is a Nissan Leaf.