The Sinews of Peace. Why Did a Descendant of the Land Rover Series I Get an Aluminum Body Aga

In 1946, the outstanding British designer Maurice Wilkes began to develop the Land Rover Series I. This car remained the most popular SUV in the world for many decades.

At the same time, another great Englishman Winston Churchill gave his famous speech on the post-war structure of the world in Fulton, Missouri. Strangely enough, the speech can be easily linked to the development of the British automotive industry because the first all-terrain Land Rovers just became the “Sinews of Peace” and the ideas embodied in these cars have been developed today – with the release of the new Defender generation.

The Sinews of Peace. Why Did a Descendant of the Land Rover Series I Get an Aluminum Body Again 70 Years Later? photo 2

In the second half of the 1940s, the British government, trying to feed the country's war-weakened economy with hard currency, rigidly quota the sale of steel. For example, the companies, which sold cars abroad, made more money than others. Rover Company did not actively promote import, so it only had enough steel to build frames for its first SUVs. The rest parts were made of aluminum, which was prepared in large quantities for the aircraft production and remained unclaimed after the end of the war. Why did the British decide to go back to aluminum these days? Is it possible to combine strength and lightness?

Let's answer another question first: is it possible to use a small piece of ordinary paper to make a stand for a mobile phone? It turns out that this is easy: if you roll a sheet of paper into a cylinder and glue its edges together, you will get a device, which will hold not only a mobile phone but also, say, a heavy billiard ball. You can also do it without glue at all – make an «accordion», lay it down on the edges and put your gadget on it. Oddly enough, the car design developed along the same principle. However, the engineer had nothing but a slide rule, a T square and an arithmometer in «computer-free» times. Because of this, many ideas remained in the minds of designers who did not have the necessary computing power at hand. Now — a completely different matter! The time has come for the most ambitious plans and the most difficult tasks to be accomplished.

Winston Churchill next to his SUV in 1954 – when he again headed the government as during the war years Winston Churchill next to his SUV in 1954 – when he again headed the government as during the war years

Nowhere without a frame!

Once, engineers did not think of a car without a frame – it does not matter whether it is large, small, for two people or for a ton of cargo. It seemed that the construction of two channel bars and several crossbars would never be replaced. Over the years, trying different monocoque structures, including spatial frames, designers came to the conclusion that it was very possible to produce cars without this pile of metal and it would be even more correct to do so: the car would become lighter and its handling would improve without the frame. You will probably be surprised to learn that USSR-based NAMI (automotive institute) designed (and built) a bus for 38 people with the monocoque body even before World War II.

It was easier and cheaper to make an aluminum body than a steel one. In addition, Rover’s engineers simplified the manufacturing process as much as possible It was easier and cheaper to make an aluminum body than a steel one. In addition, Rover’s engineers simplified the manufacturing process as much as possible

Long story short, the monocoque body began to gain popularity in the industry even before the war. The civil automobile manufacturing was curtailed in both Europe and Japan. The US car industry in pursuit of government orders was re-arranged on military rails, and military all-terrain vehicles were exclusively frame-mounted. They carried a light gun, delivered several wounded to the hospitals and could get through places where the horse and cart were bogged down.

The frame design provided quick mounting of any body type of all three postwar Land Rover series The frame design provided quick mounting of any body type of all three postwar Land Rover series

Did the designer of the first Land Rover, Maurice Wilks, think about the monocoque body when he operated one of those military all-terrain vehicles in his farm in the postwar period? What would the first Land Rover have been like if a British engineer had had enough steel? Well, who knows? In any case, the frame was frequently used in the production of SUVs. There were many reasons for it – from rational and engineering reasons to emotional and consumer ones, which, as usual, had nothing to do with reality.

Let's start with rational reasons. The Land Rover was necessarily multifunctional like any other military vehicle: it was used for plowing, supplying power to a sawmill, shoveling snow, driving a huge trailer of hay to sheep, fighting fires, delivering the sick to the hospitals, dispersing and even arresting particularly aggressive demonstrators along the way. Oddly enough but all this bouquet of opportunities was possible due to the frame in those years. Tow hooks, winches, power take-offs, pumps and other devices were attached to the frame crossbars. It was the frame that made it possible to easily change the “superstructure” or the body without any extra costs. Not the least, the car demonstrated its remarkable traction capabilities due to the fact that aluminum panels, which were produced mainly on bending equipment and not by expensive stamping, were light and did not consume power from the engine. At the same time, the body provided full protection from rain and wind in contrast to the awning, which was used with many SUVs back then.

Thanks to the steel frame and lightweight aluminum body, the Land Rover Series I did not turn over even with a roll angle of 45 degrees Thanks to the steel frame and lightweight aluminum body, the Land Rover Series I did not turn over even with a roll angle of 45 degrees

Besides, the frame allowed constructing of several configurations on one wheelbase with minimal costs: it was enough to change the length of the longerons, move around the rear axle with suspension, release a new driveshaft – and a new car is ready! In general, the frame had many advantages at that time. For example, it provided a low center of gravity at a great height of SUVs. The lightweight aluminum body lowered it even more – according to this indicator the Defender was the best. Moreover, the car was super-stable, allowing for a very large roll rate. When used off-road, the frame reliably withstood any load. Shortly, it is not surprising that it seemed to be an eternal non-alternative design for this type of cars for a while …

The previous generation of the Land Rover Defender: the cars are assembled slowly and mostly manually The previous generation of the Land Rover Defender: the cars are assembled slowly and mostly manually

As time went by, all ordinary passenger cars have moved to monocoque bodies – they have lost weight, gained in handling and safety. The designers of cars, especially of large frame SUVs, have not thought about safety for the longest time. However, let's deal with one popular stereotype: it is believed that the frame, due to its solidity, reliability and rigidity, is much safer in a collision than the monocoque body. Oddly enough, this theory has long occupied the minds of engineers, at least until they began to investigate the distribution of power flows in a collision. It turned out an amazing thing: the stronger the car was, the less chance of survival the driver had, which was confirmed by the first measurements in the laboratories.

The monocoque body allows designers not only to create zones of programmable deformation but also to take away the load from the driver and passengers. The frame, on the contrary, only contributes to maximizing of damage received by passengers.

It is not easy to shorten or extend the wheelbase on a monocoque body: in fact, you have to design it again It is not easy to shorten or extend the wheelbase on a monocoque body: in fact, you have to design it again

Obviously, the monocoque body has its drawbacks because, as we know, there is no such thing as a free lunch. It is no longer so easy or cheap for engineers to make a model with a new wheelbase size – to do this, you need to actually design the body from scratch, not only increasing the key elements in length but also strengthening them or increasing the thickness. So, it is almost impossible to produce convertibles because it entails the deterioration of some of the car characteristics due to a radical increase in weight.

Yes, if you didn't know, a convertible is always heavier than the car with an all-metal body, on the basis of which it is made. The fact is that the roof is one of the key power elements that is involved in the distribution of the load in a collision and gives rigidity to the whole structure. When designing a convertible, engineers have to resort to strengthening its bottom. Other tuning companies, which occupied the whole state of California, offer a much more elegant solution: they simply weld the doors; otherwise the car will fold in half on the nearest bump or speed breaker. Still, the monocoque body has disproportionately more advantages than disadvantages, even from the standpoint of the SUV production.

Computers and aluminum are power!

How to combine the strength and rigidity of the frame with the characteristics of the monocoque body? Here, computer capacities, which multiply increased over the past three decades, along with old theoretical mechanics and strength of materials, have come to help engineers. In fact, why not use computers, relying on the results of scientific achievements, to select the optimal profile of the power element depending on the expected load? Those calculations that used to take months can be done in a minute today. Actually, the mass of the car element becomes the boundary condition: the mass should be as small as possible but the choice of the metal thickness and such quantities as the polar moment of inertia can be left to the computer. By combining all the characteristics, you can quickly get your own stress-strain state options for different designs. The stress-strain state is, simply speaking, the stress that occurs in the detail when the load is applied.

The Sinews of Peace. Why Did a Descendant of the Land Rover Series I Get an Aluminum Body Again 70 Years Later? photo 3The Sinews of Peace. Why Did a Descendant of the Land Rover Series I Get an Aluminum Body Again 70 Years Later? photo 4The Sinews of Peace. Why Did a Descendant of the Land Rover Series I Get an Aluminum Body Again 70 Years Later? photo 5The Sinews of Peace. Why Did a Descendant of the Land Rover Series I Get an Aluminum Body Again 70 Years Later? photo 6The Sinews of Peace. Why Did a Descendant of the Land Rover Series I Get an Aluminum Body Again 70 Years Later? photo 7The Sinews of Peace. Why Did a Descendant of the Land Rover Series I Get an Aluminum Body Again 70 Years Later? photo 8The Sinews of Peace. Why Did a Descendant of the Land Rover Series I Get an Aluminum Body Again 70 Years Later? photo 9The Sinews of Peace. Why Did a Descendant of the Land Rover Series I Get an Aluminum Body Again 70 Years Later? photo 10The Sinews of Peace. Why Did a Descendant of the Land Rover Series I Get an Aluminum Body Again 70 Years Later? photo 11

Obviously, this is just in words only but now it can be done at least quickly! However, don't forget that the new Defender should have been better than the old one not only in terms of maneuverability but also in terms of traction properties and the bearing capacity of the elements. For instance, the static load on the roof of the new SUV is an absolutely unimaginable 300 kg and the snatch load on the tow hook can reach as much as 18 tons!

It is clear that the metal thickness of the bearing elements must be increased in order to achieve such properties. Will there be any benefit in giving up the frame and using a heavy steel monocoque body? And here lightweight aluminum comes to the aid of engineers because it is almost three times lighter than steel. The necessary strength has been achieved, the necessary level of safety has been ensured, the traction properties are now better than before, while the car weight has remained the same and has not increased. But what about steel? Isn’t it applicable to the modern Defender? It turns out that it is! The Defender is fitted with subframes made of steel. They add extra strength and rigidity to the lightweight aluminum body.

So more than 70 years later, the new Defender, which was designed with the help of modern computer technologies and made of aluminum, has become the direct heir to the Land Rover Series I model of 1948.

And yet people in the production of SUVs are still needed! And yet people in the production of SUVs are still needed!

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