*2.1. Operation of the Hay Inclined Plane*

To give the reader a complete idea of the analysis of the invention of William Reynolds, it is necessary to explain its operation. An exhaustive description of the mechanism is included in the article published on obtaining the 3D model [13], so a more summarized description will be given here.

Figure 1 shows an isometric view of the mechanism after its computer-aided design (CAD) modeling, and Figure 2 shows a plan of the ensemble with an indicative list of the different elements that form it. Figures 2–4 will serve to illustrate the operation of the mechanism.

**Figure 1.** Isometric view of the Hay inclined plane.

**Figure 2.** Plan of the ensemble with an indicative list of the different elements.

#### 2.1.1. Upward Movement

For the ascent of the boats (12), the tugboat (11) waited in the lower partially submerged part. The boat loaded with the material to be transported was placed on the tugboat, and they were tied together with a chain. After sending a signal to the operator of the upper station, a rope pulled the trailer, helping it to ascend on the rails (13).

The rope (10) that pulled the boat was picked up in the upper station on the AA axle drum (6) after going through some pulleys (2). As the axle rotated, the rope was coiled and the boat ascended. To move this axle, a steam engine was necessary, which moved a series of gears. An adjacent steam engine, of which only the chimney and the brick building where it was housed remain, operated

an inertia flywheel (18). The wheel was solidly attached to the DD axle (17), which had two gears. The distal gear, which was the smaller gear, was coupled to the CC gear (19), which was the larger gear, which was solidly attached to axle AA, so that for each turn of the inertia flywheel the AA axle rotated 0.098 times in the opposite direction.

At the same time, the DD axle had a gear close to the inertia flywheel larger than the distal one. This gear meshed with an intermediate shaft, axle BB (15), which finally transmitted the movement to axle EE (7). For each turn that the inertia flywheel gave, the EE axle rotated, in the same direction, 0.14 times. A second rope pulling the tugboat that was in the upper channel was wound onto the EE axle drum.

To prevent the load from falling, or when it was necessary to move more slowly, two brakes could be used that braked the AA axle (4) or the EE axle (9) independently. For this, each axle had an inertia flywheel on which the brake was held, so that when pulling one of the braking levers (20) and (21), a collar embraced the wheels (8) and (5), respectively, and reduced the speed of the axles by friction.
