Wrenn started to design and manufacture a range of slot racing cars in the late 1950’s, which is back at the very beginning of what is recognised as the dawn of commercially available slot car racing. It is arguable who, between Scalextric and VIP, really started producing the first commercially available slot cars and sets, although MRRC had already been supplying model cars and accessories for the popular model car rail racing hobby back in 1957, which was the limited precursor of slot car racing, and some enthusiasts still believe that they were the true originators of the hobby All of these companies were followed very closely by SRM and then also by another company that was already well established and respected in the model railway field, G. & R. Wrenn Limited.
The Design of Wrenn Formula 152
What was remarkable about this venture was the fact that the cars were to be produced in the unusual and very small scale of 1/52 and at that time no manufacturer had an existing electric motor small enough to fit into these tiny cars. So literally the Wrenn designers started with the proverbial ‘blank sheet of paper’ and produced a Vibrator-type motor which could run on either an AC or DC electrical supply. It was envisaged right from the outset that the Wrenn Formula 152 system would include many innovations, the unique one being the independent control of up to three cars on either lane, hence the title – ‘Triple Electric Model Motor Racing’. This revolutionary system was made possible by having two pick-up strips on either side of the slot in the track and the collector brushes underneath the cars having the facility of being adjusted to pick up from either of two positions. A special Deflector Straight was quickly introduced to enhance the facility of being able to race three cars on each lane and it provided a unique way of moving a car from one lane to the other for overtaking. The small size of the system meant that quite interesting layouts could be assembled on the proverbial dining room table and even simple layouts could create more interest with this overtaking facility.
The very first official appearance of Wrenn 152 was at the 1960 Brighton Toy Fair where it was described as the sensation of the show. After this very successful launch, the new Wrenn Formula 152 was eventually made available for the public to purchase later that year, in time for Christmas. The first item that was made available was the No 1 Basic Set which was released at the end of September with additional items such as the individual Cars, Track sections, Controllers, Return Leads, the Bottle of Oil and the Instruction Manual being available from mid-October 1960 onwards. At this same time the Service Spares which included the Contacts, Collectors and Tyres were also being made available.
Very favourable reviews were appearing in the modelling press at this time and an initial ‘first impression’ review was featured in the very first issue of the newly renamed Model Maker and Model Cars magazine in February 1961. This was followed by an in depth review in the later July 1961 issue, which devoted three full pages to a comprehensive appraisal of the Wrenn Formula 152 system together with an evaluation of it’s Vibrator motor. This review article had been purposely delayed until the Deflector Straight had been launched and tested with their previously supplied set.
The First Cars and the Vibrator Motor
All of the range of Wrenn cars were Grand Prix cars from the late 50’s and early 60’s and the first two cars produced were the Red Ferrari 256 and the Dark Green Cooper T51. They featured Vibrator-type motors and this type of motor would also be used later by other slot car manufacturers such as Meccano with their Circuit 24 range but especially in HO, initially by Playcraft and then Aurora. The cars themselves had two-piece injection-moulded nylon bodies, comprising a Chassis, which included all of the internal components such as the motor etc, and a Body Top with a clear polystyrene Windscreen and they ran on die-cast white metal spoke-effect Wheels with rubber Tyres. The first two car types also featured Exhausts manufactured from die-cast white metal, however all of the later cars had these manufactured from injection-moulded Silver-Grey polystyrene. Each car featured a Speed Lever underneath the Chassis so that their maximum speed could be pre-set. This provided the facility of either limiting the car’s top speed for young children to become skilled at controlling the cars or to provide a car for the individual to race against with a pre-set speed. This was another ‘first’ that Wrenn introduced which would surface many years later in other manufacturer’s products and, in some cases, would last until the 1980’s.
Expansion of the Range
Wrenn started to expand their range and in the following year they introduced the Yellow Ferrari and the Blue Cooper. This would set the trend of having two different colours available for each type of car and would apply to all future launches. Between 1961 and 1963 new Sets were launched with all of them containing two cars but latterly some larger Sets were introduced with three cars. In 1961 two Extension Packs were also introduced to enlarge the racing circuit with one of them also including an extra car and a Controller. A range of Accessories was introduced and these were added to over the years to enhance the slot racing experience. These included different pieces of Track, Buildings, Figures, Fencing, Flags and Flag Poles.
In order to promote the Wrenn Formula 152 range a number of fully working track layouts were manufactured which were mounted onto scenic boards as self-contained units. They included items such as the racing buildings and the Landscape Sheets and some of them even included railway items from the Wrenn range of permanent way trackwork. These layouts were supplied to a number of dealers in the trade and also taken to exhibitions with photographs of them being used in the Instruction Manual and also on the cover of the Catalogues to promote the total Wrenn Formula 152 experience.
Later Cars and the DC Motor
The initial range of cars was then expanded with two additional cars this time with a late version of a Maserati 250F and a Vanwall, both available in two different colours. By 1964 the Wrenn designers had been working to improve Formula 152 and the decision was taken to introduce another custom-built motor, this time purely DC, but it was again certainly not conventional. There was a period when both types of motored cars were available and all of the previous Vibrator-motored cars were then also made available powered with the new DC motor. New Mk 2 Controllers were introduced to accompany the DC motors and these now featured a variable resistance rheostat replacing the early AC version which, like many other manufacturers of that time such as Scalextric, VIP and SRM, had originally just been basic on/off switches. Both versions of the Controllers featured a separate slider to lock the control button. When this was used with the AC version of the Controller and, in conjunction with the Speed Lever underneath the car, this gave the Vibrator-motored cars their pre-set speed.
Eventually the Vibrator-motor cars were discontinued and removed from the Price List but the Service Spares for them were still available from the factory. Wrenn continued to service these cars until all of the stock of Vibrator motor-related Service Spares were exhausted and it was then uneconomical to produce any more. In these situations Wrenn honoured the warranty and supplied new replacement DC-motored cars. The range of cars was then finally expanded with the addition of two more cars, this time a BRM P578 and a Porsche 804 and these completed the Wrenn Formula 152 range of different car types.
From their model railway experience Wrenn were well aware of the enormous potential for expanding sales with trade overseas and negotiations took place with various companies to act as distributors within other countries. During 1963/4, which was probably at it’s maximum popularity and global coverage, Wrenn stated that ‘Formula 152 Motor Racing was already popular in 40 countries’ obviously making it truly international!
The Later Years of Production
Looking at the slot car modelling press of the time it was becoming increasingly noticeable that the larger dealers were not stocking the Wrenn Formula 152 sets any more and whether their popularity had just been diminishing coupled with increased competition, which was much cheaper to buy, all seemed to contribute to the eroding of Wrenn’s position in the marketplace which may have prompted some significant later decisions within the company.
At the end of 1966 Wrenn decided to change its marketing strategy by offering three very different special sets. These included everything that was needed to assemble a fully working layout with all of the Accessories such as a Lap Counter, Track Pits and Grandstand buildings, Flags and Flag Poles, Track Personnel and Spectator figures that had previously been available separately up until that time. These sets were all advertised to be sold at half price so these were priced to be very competitive.
Later the following year*, the company decided to introduce a range with a third type of motor. These were much cheaper to produce than the previous versions and, in fact, this introduction of a cheaper range had been initially suggested back in early 1962. As the decision to introduce this new range was more than likely a political one, as yet, there isn’t enough information available to fully comment. Various rumours do exist regarding the Lines Brothers buy-out of Wrenn and the implications to the future manufacture of Formula 152 with Lines Brothers already having their Scalextric range, but nothing has been confirmed.
The 9-Volt Motor
The final motor which was decided upon was a very strange choice It was known as the ‘MAXIMISER’ motor and had actually been available since 1964. It had been used at that time in the Wrenn “Master Mariner” set which was a toy/game involving a small paddling pool of water and a remote-controlled battery-driven model ship. I will not go into further detail here but suffice to say that being a Wrenn product it was, as usual, quite innovative. Anyway the motor itself featured open copper windings around a soft-core magnet, it worked off 9 Volts and was, unfortunately, physically larger than either the previous Vibrator or even the DC motor. The original motor was enclosed underneath a Grey cover but, in order to reduce the motor’s size for insertion into the cars, this had to be removed. Even then the size did cause an issue in that only two of the existing range of six car bodies could accept the new motor, the Vanwall and the Maserati. The cars were designed to be used with a 9-Volt battery supply but the motors did not have enough torque to start the cars from rest. This meant that at the beginning of a race and also when the cars became de-slotted they had to be push-started, just like the real thing! Indeed the Wrenn marketing department used this as a selling point and advertised it on the set box lid stating – ‘Racing-style Push-start New type Motors’.
The Final Set and the End
Only one set was produced in this final range which included two Cars and Controllers, a figure-of-eight Track, Fencing and Fence Posts, two unpainted 1/52 scale Figures from their range and the obligatory Bottle of Oil. The Controllers in the set were the original AC type, featuring just the on/off button, and the cars were produced more economically this time with Pale Grey injection moulded Exhausts. They only had number roundel transfers applied with no Silver painting for the highlighted details as of the previous cars. These cars even had oversize Collectors, which were pieces of braid the same size as those used on 1/32 cars, replacing the normal custom-made brushes. This was obviously a conscious decision and meant that the braids swept over both sets of the track pick-up strips so that multi-car running in each lane had to be forsaken and obviously also lane changing. Apart from the set a list of additional Cars, Track and Accessories that were available was printed stating that all of these items were now only available direct from the manufacturer.
This final attempt was the last death-throw of a company that had less than ten years earlier established itself at the forefront as a serious and possibly the most ingenious slot car manufacturer. Over the years, especially during their early period, the company took it’s initial innovative product, continually invested in developing it further and adding to the range of Accessories but unfortunately this all ultimately ceased just after the mid 60’s leaving a wonderful legacy. However the company did not end there but Wrenn significantly expanded their production of items in the model railway field to include locomotives and rolling stock, going on to have many more successful years of existence.