by Andrew Woodmansey
This article explores how intelligent caravan layouts can save on materials and fuel whilst retaining many home comforts and improving towing safety.
New caravan buyers often like to take the comforts of home with them when travelling. These often include full size beds, ensuites and washing machines. Caravan manufacturers are only too happy to oblige by producing long caravans that include these features and more. Slide-outs, which increase the width of an RV, are increasingly seen in caravans to create extra space.
The long caravans needed to accommodate the creature comforts of home are also heavy. So called ‘off road’ caravans also weigh more than their tarmac-constrained cousins because of the heavier materials used in their construction. On the whole though, there is a close relationship between caravan weight and length. Shorter caravans tend to be lighter because the quantity of materials used in their construction is less – one linear metre of aluminium weighs half as much as two. Depending on the type of caravan and the facilities it contains, one foot of caravan length has been said to equate to about 100 kg in weight.
As readers of the Caravan Buyers Guide will know, heavy caravans carry a higher risk of instability under tow than lighter ones, especially if weight distribution is poor. They are more difficult to extract from mud and sand and use more fuel to tow. The number of tow vehicle options are already very limited for heavy caravans and will become even more so as tow vehicles must become lighter to comply with new global vehicle emissions standards.
Experienced caravanners tend to take less gear with them over time rather than more, because through experience they become acutely aware of the fuel and instability penalties of a heavy load. They also know what they can do without, something that can rarely be said of new caravan buyers. For these reasons it is not uncommon for a family’s second caravan to be shorter and lighter than the first one.
Intelligent caravan layout design can help reduce both the length and weight of a caravan without compromising on creature comforts. Take this typical 18 foot caravan layout:
Typical 18 Foot Caravan Layout – not to scale
This caravan includes a 6 ft long island ‘queen’ bed, an L-shaped diner, a kitchen with sink, fridge and cooker and a full ensuite. Whilst the weight of this caravan will vary depending on the type of caravan (e.g. pop top or full height), the method of construction used and its intended purpose, let’s say its tare weight is 2,000 kg and ATM is 2,400 kg. The difference between the two, i.e. 400 kg, is the allowable payload for this caravan.
Now let’s have a look at another caravan, this time a 2 foot shorter, 16 foot caravan:
16 Foot Caravan Layout (Night) – not to scale
The features contained in this 16 foot caravan are the same and the bed size is identical. So where did we save 2 feet? Aha, you will say, you’ve moved the door, stuck the bed in front of it and eliminated valuable bench space in the kitchen, all of which is totally impractical. But did you notice the ‘Night’ in the heading? That’s what this caravan looks like at night. Let’s see how it looks in the daytime:
16 Foot Caravan Layout (Day) – not to scale
This caravan has had some small but significant layout changes made to it based on a good understanding of how the space inside a caravan is used at different times of day. The key changes are:
- The 6 ft long queen bed is hinged at the 4 ft mark. The last 2 ft of the bed drops down vertically when not in use during the day;
- The kitchen bench is hinged at the bed end, allowing it to be raised during the day and lowered at night when not in use.
The two key usage patterns that allow this day/night configuration are that most people don’t use their beds during the day, and that most people don’t cook at night. Additionally, you don’t need to use the caravan exit door whilst in bed (although careful consideration should be given in any layout to exiting the van at night in an emergency).
There is also improved use of some of the ‘wasted’ air space above any bed by raising it higher off the floor to allow a significant part of the foot of the bed to be lowered (as opposed to the bolsters or short metal bed extensions sometimes offered today). A higher bed would in itself be no bad thing for many caravan owners because there is less stooping involved. It is intended that the bed would be raised and lowered whilst still being fully made, eliminating the need to make the bed each night. Indeed all of these changes are intended to avoid any assembly or rearrangement of furniture or bed making at the end of a long day’s travel.
For those caravan designers out there (to whom this layout is offered as a challenge), some design details that could be considered are:
- dividing the last 2 ft of the mattress lengthwise to allow half of the bed to be used in daytime mode and the other half in night time mode (to allow daytime use of the bed by one person);
- use of a thinner mattress element for the last 2 ft of the bed (which in any event only carries the weight of lower legs and feet) to reduce the space taken up by the mattress whilst in the vertical position;
- an electric bed lowering mechanism operable whilst in bed (which could be an extension of the hydraulic mechanism used in some caravans to reveal the underbed storage area);
- retention of (more limited) underbed storage with access from each side of the bed;
- possible dual use of the folding kitchen bench as a computer workstation whilst sitting on the bed.
The design principle that lies behind these space-saving ideas is the dual (or in this case overlapping) use of night and daytime spaces instead of dedicated zones for each. The classic example of this in the home environment is the sofa bed. By converting horizontal planes into vertical ones at different times of day using simple folding mechanisms, space, length and therefore weight is saved. Using our formula above, a 2 ft reduction in caravan length might save us 200 kg in caravan weight (down to 1,800 kg tare) and potentially the same gain in payload (if the ATM is kept at 2,400 kg). Alternatively, maintaining the payload at 400 kg would reduce the ATM of this caravan to 2,200 kg.
These simple layout changes will also reduce fuel consumption and increase the range of tow vehicles that that tow this caravan. This exercise in exploring intelligent caravan layouts is an example of why the design of small spaces such as caravans can be so exciting.
Inevitably there will be many more such ideas out there. We hope that innovative Australian caravan manufacturers will take up the challenge.