Design
When designing a new model, two factors have to be balanced when considering how many components to use. On the one hand, the fewer that are used, the simpler the production process and consequently the lower the costs. A good example of this approach is the Dinky military range. On the other hand, the more components, the more detail can be included, and features added into the model. Solido vehicles are big and chunky, so there is certainly room for lots of parts. To examine the Solido approach, let’s start with a fairly complex machine – a military half-tracked personnel carrier of WW2, the SdKfz 251.
The SdKfz 251/1
During the 1930s, Germany was focussed on developing a mobile warfare capability that would become known as Blitzkrieg. Experience gained during the Spanish Civil War showed that although tanks were a powerful attacking weapon, without infantry support they were vulnerable in close terrain. There was a need, therefore, for an infantry transport and fighting platform that could keep up with tanks, even across rough terrain. Wheeled vehicles would find this challenging, and fully-tracked armoured vehicles were too complex and expensive. The chosen solution was a half-track, based on a contemporary artillery tractor designed by Hanomag.
The SdKfz 251 was put into production in 1939, and served throughout the war with more than 15,000 of various marks being built, many but not all by Hanomag. The specific version of SdKfz 251 represented by the Solido model is the early-war Mark B version.
The vehicle was armoured against enemy small arms, could carry an infantry section of 10 men, and was equipped with 2 machine guns, one in a forward position from where it could provide fire support for the carried Panzergrenadiers, and the other at the rear from where it could be used as an AA weapon. With a top speed of 32mph and good cross-country performance, it could follow behind tanks in attack, transporting troops close to, or into, enemy positions that the tanks could not deal with from where they could debus and attack (or even, on occasion, fight from the vehicle). In defence, it was useful as a means of evacuating troops from forward positions, while under fire.
The half-track was open-topped, and thus vulnerable to artillery or grenades or attack from elevated positions – hence it was seldom used in built-up areas. On the other hand, it allowed good situational awareness for the carried troops, who could also fire from the vehicle and disembark quickly by simply leaping over the sides. Infantry could use the large rear doors to embark or disembark.
The interior of the vehicle was open with no division between the driving and fighting compartments. The armoured sides at the back were bulged, which improved carrying capacity and the armour protection.
The Solido Hanomag Half-Track
Solido 7150/11B Hanomag SdKfz 251/1
Year first produced:1989
L119xW45xH44, Metal 207g, Scale 1:50, Features: 2
The Solido SdKfz 251 was first released in 1974, but our model dates from 1989. It formed part of a series of 12 different models created in commemoration of the 45th anniversary of D-Day, and supplied in display boxes.
The model shows the angled, armoured hull that enclosed the engine compartment and driving positions, and shielded the troops carried at the rear. Under the front of the vehicle is a standard pair of road wheels, and at the rear the rather complex set of tracked wheels. The model sports the typical Solido metal tracks, and all of the wheels rotate freely.
The casting carries an interesting set of marks on the bottom of the hull:
“solido”, “MADE IN FRANCE”, “44/89”, “H-K HANOMAG SD.KFZ 251/1” and “1.74 No 241”.
These require some explanation. The “44/89” marking refers to the 45th anniversary of D-Day, i.e. 1944-1989.
“H-K” is probably shorthand for Halbkettenfahrzeug, or half-track.
HANOMAG was the firm that designed the 251, and built most of them.
“SD.KFZ 251/1” refers to the military designation of the vehicle, the Sonderkraftfahrzeug (special motor vehicle) 251/1. 251 identified the vehicle, while the 1 after the slash specified the variant of the vehicle, in this case the standard troop transport. Other variants included ambulances, command vehicles, engineering vehicles, and those armed with a variety of heavy weapons.
“1.74” is probably the date that the moulds were made (January 1974). “No 241” is the original Solido model number from 1974.
The model is painted in a sand colour, suggestive at first glance of vehicles serving in North Africa. However, given the D-Day association this is more easily explained by the mid-war change in German practice from painting their military vehicles grey to using dark yellow instead.
The final element to the model is the included accessories – two plastic machine guns for attachment to the front and rear of the passenger area, a set of decals and a “plan de pose” showing where the decals should be positioned. It also apparently indicates how a brown and green camouflage pattern can be painted onto the model. The pattern looks very rough and ready – not at all like some of the more sophisticated camouflage schemes often seen on German vehicles – so perhaps it is meant to represent hastily applied field camouflage, perhaps smeared mud?
Components
To understand how many components make up the Solido half-track, we will need to disassemble it and keep a count. Before starting this, let’s begin the process by considering the accessories that were supplied with the model and were intended to be fixed to it – the set of decals and the two plastic machine guns. So, we start with a count of 3.
Thankfully, it is possible to take the Solido model apart without requiring more than a screwdriver. Underneath the model there are two screws which attach the body of the vehicle onto the bottom plate of the hull. Loosen them and the body lifts off, revealing underneath the most complex part of the model, the running gear. Don’t forget those two screws! Parts count: 5.
Now, the real-life 251 was steered by the driver using a standard round steering wheel. A slight turn would turn the front wheels only, which would be enough to turn the vehicle in a wide arc. If a tighter turn was required, turning the steering wheel more sharply would engage a differential slowing of the track on the inside of the turn compared to the track on the outside, causing the vehicle to slew round.
Sitting on the bottom plate are a total of 9 axles. The front axle carries the ‘normal’, untracked wheels. It fits into plastic wheel hubs, each fitted with a hard rubber tyre, for a subtotal of 5 items. Parts count: 10.
Behind this are 8 axles that collectively hold the tracked running gear. On the axles are fitted two types of wheels, all of them single plastic components, adding up to 24 items. Parts count: 34.
We should pause here because Solido has taken some liberties with these wheels. On the actual 251, the front pair of tracked wheels were the drive wheels, i.e. they imparted movement to the tracks. As such they were equipped with teeth to engage in the tracks, and the hubs looked different to the other, road wheels. Solido have ignored this and used normal road wheels.
Furthermore, the 251 had interleaved road wheels, where single and double wheels were alternately fitted and spaced so that they overlapped each other. The single wheels fitted into the space between neighbouring double wheels (or, to put it another way, the double wheels fitted in front of, and behind the single wheels). This allowed more wheels to be packed into the available space thus spreading the weight more evenly across the tracks, and improving traction over soft ground (but it was a complex arrangement that caused maintenance challenges). Solido modelled this interleaving, but swapped the single and doubles around so that whereas in real life the 251 had 4 single wheels and 3 doubles, the Solido model has 4 doubles and 3 singles. I’m not sure why they did this. Maybe having a double wheel at the back gave a more secure fit with the tracks?
You can see the difference by comparing the photo of a real 251 in this story with the look of the model, and noting which wheels are to the fore and which recede. It’s subtle but obvious once you notice it.
One final component in the Solido running gear is a spring, braced against the axle holding the drive wheels. This allows the drive wheels to be moved backwards, thus reducing the tension on the tracks and allowing their removal. Parts count:35.
Being half-tracked, the rear group of wheels were fitted with metal tracks. It’s here that we see Solido’s cunning patented and novel feature, the representation of these tracks not by rubber or plastic bands as most manufacturers have done before and since, but by diecast metal assemblies of individual links that fit into each other. The amazing thing about these metal tracks is that, like the originals, they are articulated (the links are connected but move individually) but they are created in a single mould as ready-made lengths of track rather than requiring assembly from separate links. So how did Solido manage this?
This is difficult to explain, but here goes… Firstly, we need to understand that at one end of each track link there was a transverse pin, and on the other end two loops into which the pin from the next link would fit. The mould created each link simultaneously in one casting action by providing it with a separate injection point for the molten metal. Furthermore, the mould included collars on each side of each link, which were inserted to keep the transverse pin on one link physically separated from the surrounding loops on the next link.
The result was a length of connected track links. In the case of the tracks on the Solido 251, each full track was composed of two such lengths. The end-most link of each length was cast without the transverse pin, but with a hole instead, so that a pin could be inserted once the other end from another track was placed over it.
Phew! Did you follow that? Luckily, we just need to decide how many parts we will count for each track in our tally of components. As each track length was cast in one action, I will count it as one component. Thus, each track is composed of 4 parts – two track lengths and two connecting pins. Parts count: 43.
Of course, all of the wheels and tracks lay on the bottom plate of the hull. Parts count: 44.
Now, let’s turn to the body of the vehicle, that we detached from the lower plate at the beginning of this process. Upon examination, we discover that there is a third screw on the underside of the body near the front, normally hidden from view. Unscrewing this reveals that the body consists of two main metal castings, an upper and lower half, which join at the point where the angular body is at its widest. They are held together by the screw and also by inserting a lug at the rear of the top half into a corresponding slot in the lower half. Fitting into a recess in the lower half of the body is a plastic spacer, which sits over the axles laying on the lower hull plate to keep them in place. Parts count: 48.
Taking a closer look at the floor of the vehicle interior, we can see the openness of the vehicle interior, and some nice texturing to the seats and floor. A plastic steering wheel is fixed to the underside of the upper hull body, while a separately cast metal gun-shield is fixed on the top around the attachment point for the forward machine gun. Sadly, although the rear doors are marked on the outer surface of the body castings, Solido chose not to make them openable, which would have required casting them as separate parts. Parts count: 50
In Conclusion
We have seen that the model consists of a total of 50 parts. In fact, the majority of the vehicle is composed of very few – just three Mazak castings form the bulk – and just a few additional details are added where these would really be noticed (the machine guns, steering wheel and gun-shield). The overall impression here is simplicity.
The majority of the parts used compose the running gear. This was necessary because Solido wanted the running gear to be functional, but it also helps to provide a level of detail that is pleasing. Even here, we can see that some simplifications have been made to keep the number of pieces as low as possible (for example, by casting the double wheels in one piece), and of course Solido were able to capitalise on their trademark method for casting lengths of track.
We should also consider to what extent parts are unique, or standardised and used in multiples. In our example, the 50 individual components consist of only 17 different items (and of these, most including the axles, front wheels and tyres, track pins, screws and machine guns are ‘standard’ parts also used in other Solido models).
I think Solido steered a middle course, doing what they could to reduce the number of parts, but retaining a fully-functioning system of wheels and tracks. Nevertheless, it’s easy to see that the 251 is still a relatively complex assembly. But perhaps the most amazing thing about the model is that, having disassembled it, I was able, contrary to my expectations, to put it all back together again without the slightest problem. Now that’s engineering!
SEE ALSO…
The contemporary US vehicle to the SdKfz 251 was the M3 half-track, produced in large numbers during WW2 and remaining in service long after that war ended. Solido’s model 244 captured it nicely (though they opted not to use their trademark articulated metal tracks, substituting ribbed rubber bands instead).
As you might expect, French armoured personnel carriers are well represented in the Solido range. These include 227 AMX-VTT (a tracked armoured troop transport, based on the AMX-13 tank), 254 AMX-10 (a tracked vehicle that replaced it), and 251 VAB (the other replacement vehicle, this time wheeled).
Fighting Toy Stories 