From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Guide on planning car comfort, focusing on seating dimensions and selecting a vehicle based on passenger stature.
Identifier | ExFiles\Box 117\1\ scan0055 | |
Date | 12th November 1935 | |
The Motor 748 November 12, 1935. Contd. PLANNING CAR COMFORT FRONT SEAT COMFORT Suggested front-seat dimensions which should be considered from the point of view of full support under the thighs and general comfort. AN INCORRECTLY DESIGNED SEAT STRAIN & FATIGUE A low, flat seat layout of this type is invariably found to be uncomfortable after a mile or two. [Column 1] average height, so long as there is also toe-room under the front seat. Layouts of this type are used on many cars to-day, especially as the rear seat has been brought forward within the wheelbase to increase riding comfort. An alternative dimension which could be taken in such a case is that from the edge of the rear seat cushion to the toe point underneath the seat; the minimum required is 22-24 ins. The provision of toe-room is absolutely essential, otherwise the heel will fall behind the knee line and the restful posture is lost. In practice this arrangement of short knee space and adequate toe-room works out very well as it can be used with a soft, reclining squab. In cases where the floor level is flat throughout, the seat cushion is invariably only 10-12 ins. from the floor, so that much more leg-room between the front seat and the cushion is demanded. It must be at least 16 ins. or 23-24 ins., measured from the front of the seat cushion to the point where the heel would fall. This will allow of a comfortable reclining position with room to move about. More Detailed Considerations The foregoing are generalized suggestions for persons of about 5 ft. 8 ins.-5 ft. 10 ins. in height and of average leg length to overall height proportions. If the car is to be selected with a view to meeting more detailed requirements, then a little more careful measuring should be adopted. As the main consideration is that of legroom, the dimensions to be taken are those from the base of the spine to the knee and the knee to the heel; a combination of these two giving the overall dimensions from spine to heel is one of the most valuable, as a c18 [Column 2] matter of fact, for determining whether the seating will suit one or not. Do not forget also to make an allowance of an extra few inches for the toes. See the sketch on the previous page for this dimension. The measurement should be taken at the back of the leg as this is the part which is in contact with the seat cushion. Such dimensions can easily be checked up on the car under consideration, but remember that the base of the spine is not located right at the back of the seat cushion, but usually some three or four inches from the squab. Measuring for Head-room For head-room, the measurement should be taken from the seat to the crown of the head, as already indicated, and when armed with these sets of figures, one should be able to find the car which will suit the tallest of one's regular passengers. To give real comfort, the cushions must support the full length of the thighs and take the weight to prevent its all being thrown upon the heels. It is for this reason that we have suggested taking the dimensions on the under side of the thigh and leg to make sure that the seat really does follow the body contour. The short man is often neglected in body designs in which there is a tendency to drop the seats and raise the window line at the same time. Thus the unfortunate person of small stature can hardly see out of the windows except to peer up at the sky. Otherwise practically every seat will house a short person comfortably. Incidentally, the tendency to bring all seats within the wheelbase has done much towards increasing riding comfort and it has enabled a wider leading edge of the cushion to be employed giving greater facility for carrying three persons abreast than used to be the case. There is another advantage accruing from this feature of design, namely the easier entry to and from the rear compartment, as the wheel-arch does not intrude so far into the doorway as would occur if the whole of the seating were placed farther back. This is shown adequately in one of the accompanying illustrations. Front-seat Design A point concerning the front-seat design which is well worth bearing in mind is that of the height of the cushions. Even now various manufacturers tend to keep the seat cushions rather flat and only a few inches above the floor level. The net result is that the whole of the weight of the body is taken at the base of the spine, there being no support under the thighs at all so that the calves and knees are strained. After only a few miles this sitting position becomes extremely unpleasant and very tiring. A comfortable cushion height is one measuring 11-12 ins. from the floor level with a cushion depth of about 20 ins. and a squab of 22-24 ins. in height. This combination really does give excellent support, all the more so if the squab is made to swell out slightly at the base, filling in the hollow of the back. [Image Caption] Another point to consider is the ease with which passengers can get into the rear compartment; note to what extent the rear wing cuts into the door space. This Flying Standard is an excellent example of easy entry. --- PAGE BREAK --- X1021 November 12, 1935. 745 The Motor PLANNING CAR COMFORT How to Select a Car According to the Number of Passengers and Their Stature [Image Caption 1] Three abreast can be taken in quite a number of cars, but it is essential that there be plenty of elbow-room as well as adequate cushion width, as in the big Vauxhall. [Column 1] WHEN a man buys a car his whole family is rarely present; the selection personnel probably comprises husband and wife. Often they have received advice on technical points from the son, who, even if still at school, is sometimes sounder mechanically than are his parents. In making a selection the front seating receives the greatest attention, especially if the purchaser is to be the driver. The rear seat is tried in a cursory fashion and accepted, frequently, if it appears that "it will do." The selection personnel will probably never ride in the back of the car, anyway, so why should they worry themselves? It is only fair, however, to consider this aspect more seriously. The passengers have to endure quite a lot on a long run, and seating that is comfortable for a short town trip may soon become unbearable. There are old and young to be considered. Is the rear seat to be used mainly for children or adults? If adults, will there be two only or are there many occasions when three or more will be carried? Think of these facts and it will be realized that the question of buying a car suitable for your passenger accommodation is not quite the simple question it appears to be at first. [Column 2] On brief examination, almost any four-seater might be considered suitable and comfortable for the passengers, but a journey in it will reveal many details which do not comply with requirements. Given 16 ins. or more between the front of the rear seat cushion and the front seat squab, it will almost certainly do for two adults of average height or two or three children, who do not require much leg-room, and normally do not sit still, anyway. The most usual defect revealed by practical tests, is restricted measurement in the vital dimensions of headroom, elbow and shoulder space, and foot and leg-room. The car may be adequate for sitting in when stationary, but a little rolling or swaying, pitching or bouncing, will immediately show up its worst features; and again, when thick coats are worn, and other types of hat, it may easily be found that the vital spare inches (and they are vital to comfort) have been encroached upon to such an extent that the seating becomes a really tight fit. An easy way out is to buy a large car and have—it is to be hoped—no further trouble. Economic considerations unfortunately interfere with this policy, and the average motorist is compelled to choose a type of automobile which gives him the minimum performance which he can tolerate combined with seating accommodation that is not too cramped. This is where experience scores, for by bringing knowledge to bear upon c15 [Image Caption 2] Cars such as the Armstrong Siddeley and Riley, equipped with steering column gear controls, give unobstructed space in the front so that a third passenger (a child for example) can be taken on a bench - type seat (above). [Image Caption 3] The majority of coupes provide quite a wide seat on which three, as a rule, can easily be carried (right). | ||