A short time ago Autocar published a most interesting feature by Michael Scarlett (I wish I had thought of it first!) about going out in the “top gear” 1909 45 hp Sheffield-Simplex which Lord Riverdale has had commendably restored, and then trying to emulate the Land’s End to John O’Groats top-gear run which this type of Sheffield-Simplex accomplished successfully under RAC observation in 1911, in a modern 4.2-litre XJ6 Jaguar locked in fifth speed.
The Jaguar did not quite make the intended all in top-gear run, because it came to rest on the one in seven or steeper gradient of Berriedale hill, 34 miles from John O’Groats. However, there was some poetic justice in this, because back in 1911 the Sheffield-Simplex had also failed, on a hill near Kidderminster which was blocked by carts. It was then deemed permissible to return to the bottom and make another ascent, in top gear. In 1983 Scarlett found that he should not have been on Berriedale anyway and, after the Jaguar’s badly overheated clutch had recovered, he continued in top gear along the easier route taken by the End-to-End-All-in-Top-Gear Sheffield-Simplex. Alas, in turning round, the Jaguar’s gear-lever seal had been broken, so this run does not count for RAC endorsement.
It reminds me, however, that in 1927 The Autocar, road-testing the then-new magnificent 50 hp Daimler Double-Six landaulet, took the big car up Fish Hill out of Broadway in top gear, in spite of having to drop to 18 mph. Comparison with the XJ6 Jaguar may be interesting. The Daintier had a 7,236 cc engine to the Jaguar’s 4,135 cc. The Daimler weighed some 6,000 lb to the XJ6’s 4,291 lb and had a top-gear ratio of 4.86 to one, whereas the Jaguar had to make its “all-in-top” bid on a fifth speed geared up 0.792 from the 3.3 to one axle ratio. (To complete the comparison, the Sheffield-Simplex had a 6,982 cc sixcylinder engine, weighed 4,542 lb, and the higher ratio of its two-speed transmission was 3.0 to one. The older cars also had larger diameter tyres than the XJ6.) The Daimler had double sleeve valves, the Jaguar twin-overhead-camshafts, — the Sheffield-Simplex side-by-side valves and bore and stroke the same as that of the first 40 / 50 hp Silver Ghost Rolls-Royces, of which it is said to have been seen as a rival. . .
Fish Hill, which the 1927 Daimler Double-Six not so much climbed as “subdued”, in the words of The Autocar’s tester, quietly and easily, four up, has a gradient of one in 10, but is a long, winding gradient. These days much of it double-track, facilitating passing slower vehicles, but is nevertheless a formidable obstacle. I have often wondered whether the modern XJ12 Jaguar could emulate the performance of the old Daimler Double-St! — both 12-cylinder cars — and climb it slowly without coming off top speed? But as this magnificent Jaguar is only available in automatic-transmission form, making it impossible to hold it in top against its will, I suppose I shall never know. — WB