Somewhere in the last year I can across a recommendation to not miss the book The Secret Horsepower Race: Western Front Fighter Engine Development by Calum E. Douglas (Tempest Books, 2020). Fortunately, I landed a copy of this coffee table size (and weight) book and I don’ regret it for a moment. Not only has is shown me more of the technology behind fighter engines in World War II, it also has shown me how those very same engine designs influence Formula One racing engines of today. It also has given me a deeper understanding of various air combat wargames, and in particular designer Lee Brimmicombe-Wood’s Wing Leader series from GMT Games.

“What?”, you say. “Formula One and WWII engines are related?” Yes, and in the most interesting ways as author Calum E. Douglas explains in The Secret Horsepower Race:

Today’s engines are now bearing the fruit of the work done during the Second World War, sometimes through a ‘second discovery’, sometimes through an old idea being rekindled. All Formula One motor-racing engines have the axial swirl throttle which started as a radial design in France and was designed by Daimler and then Mikulin in axial form. It is now normal practice for Grand Prix engines to run at over 130^OC coolant temperature, for exactly the same reasons as Professor Messerschmitt complained so bitterly to Milch in 1942, and the water-cooled exhaust valve-guides of the Jumo 213 are to be found in the design of many Formula One Teams.

Calum E. Douglas, The Secret Horsepower Race, p. 458

In The Secret Horsepower Race there is an image on page 425 that shows a German Jumo 213 J connecting rod in a 1945 sketch just above a sketch of a “modern” racing engine connecting rod. Just how similar the two look is very striking and brings home the lesson of just how “advanced” the fighter engines of World War II actually are.

The Secret Horsepower Race is certainly a more technical read than I normally undertake. After all, I’m a History major, not an engineer! That said, Mr. Douglas spins a fascinating tale that, though full of technical detail, also has enough history and espionage that it really entertains. I found myself drawn in and slowing to carefully read the account.

Book to Wargame

As I read The Secret Horsepower Race I found myself thinking of several air combat wargames I’ve played. In the late 1970’s when I started playing wargames, I acquired copies of designer S. Craig Taylor’s Air Force and Dauntless (Battleline, 1976/1977). These were my first introduction to the world of air combat wargames. If there is one rule I remember from those games it’s that inline engines were more vulnerable to damage than radial engines. In the 1990’s I moved to J.D. Webster’s excellent Fighting Wings series of games where engine power was a key factor in helping one “maintain energy” while in air combat (I highly recommend the latest version of Buffalo Wings from ATO Press). In the late 2010’s it was Lee Brimmicombe-Wood and his Wing Leader series from GMT Games that caught my interest.

The Wing Leader series uses a very different air combat wargame design, most noticeable from it’s side-view of battle. It is also, perhaps, the design most closely based on the secrets of The Secret Horsepower Race:

Speed. The grand thesis of Wing Leader is that victory in air combat usually went to the swiftest. Manoeuvrability turned out to be less important than power and speed. The pre-war biplane fighter advocates lost that argument, though in the right conditions these aircraft proved to be a handful. The division of aircraft into 50 mph bands is crude, but works to define generational improvements. As the war dragged on, leaps in performance tended to be in increments of 25 mph or more.

Lee Brimmicombe-Wood, Wing Leader: Aircraft Data Card Creation, v2.2

Book to Life

Although I read The Secret Horsepower Race to learn more about aviation history, I was pleasantly surprised by the connection to Formula One racing. It also taught me more of the engineering history and mathematical basis behind the designs of several wargames. More importantly, Calum E. Douglas teaches some real life lessons that go beyond history and wargame and are most applicable to my wannabe engineer youngest. To quote Mr. Douglas’ conclusion at length:

The blood, sweat, and tears which went into making a basic engine such as the Merlin into a war winner is not manifested in some magic gadget, but is concealed in hundreds of thousands of hours spent on fundamentals of engineering; making new drawings; machining parts with precision; organising the manufacturing in such a way that parts are of high quality and are checked properly; rigorous testing; chasing faults down as soon as they emerge; and all the time pushing incrementally forward.

That is how real high-performance engine projects are conducted, and those who were not there, or who have not done it themselves, can never understand the strain a designer faces watching an engine they have been responsible for start for the first time. In this moment their entire reputation stands fragile – a failure can mean disaster and the expense of tremendous sums of money and time. The engine designer is pleased when the engine runs and does its job.

This small pleasure is not enough, as those who devote their careers to engines know just how extraordinarily difficult it is just to reach that ostensibly simple plateau. Even one tolerance written incorrectly on a drawing, one missed particle of dirt during assembly, or a simple decimal point being out of place in a calculation can spell ruin.

That these engineers were able to make hundreds of thousands of state-of-the-art engines at all during the chaos of total war is a demonstration of the indelible lesson that success depends on focused effort and above all a deep level of mathematical understanding mated to pragmatic organisational thinking. Engineers today who see the power which was wielded with only a slide-rule and pencil and adapt the same mindset to use their computers instead of being used by them, will achieve spectacular success.

Calum E. Douglas, The Secret Horsepower Race, p. 458