What's the connection between multifaceted genius Leonardo da Vinci and the great Panama Canal? Interestingly,

his centuries-old invention, the miter lock, is still utilized in the majority of the canal locks. Its design

is simple, yet miter locks form a perfect, watertight lock. People before da Vinci were using heavy, inefficient locks

that worked against gravity. Now, let's assume you are da Vinci and you installed two V-shaped wooden gates in a

flowing river. Note that the gate is hinged, and this is its open position. What do you think will happen?

You're right; the flowing water will force the gate to automatically close. Let's rewatch this animation and notice how

the angled edges of the gate ensure that, after closure, the joint formed is a neat one. The V-shape serves yet another

purpose. After the gate closes, can you guess what will happen to the water level? The water level will rise on the

right side, and there will be a small amount of water leakage on the other side. However, as the water level rises, the

pressure on the gate increases; the gates will press against each other and will seal the gate connection tightly. Now there won't be any water

leakage through the joint. That's a perfect and easy mechanism to achieve a watertight joint. The miter lock gates

form a perfect, watertight lock automatically. But how do we open them? Let's introduce balance beams on both

sides. Even if three to four people push from both sides, the water pressure is so tremendous that this gate won't

open. Before manually opening it, one should make sure that the water level is the same on both sides. Just open the

slide valves of the miter lock. Now that the water level has become even on both sides, just one person at each side can

Easily open the gate. The gate should be completely open like this, so that the boats can easily pass through. Here comes

a small challenge: when the gate angle is a perfect 90°, closing the gates will not happen automatically.

This is why the operator has to pull the balance arm. After a small angle, the water force will assist to form an

automatic watertight lock. If you've ever witnessed the engineering marvel, the Panama Canal, you might have seen this ingenious

invention of Da Vinci in action. The Panama miter locks are an advanced version of the original Da Vinci model.

The heaviest gate leaf weighs up to 730 tons. In order to operate such a gigantic gate, a powerful motorized mechanism was

installed. A strut steel arm connects the gate with a giant bullwheel. The motor drives this bullwheel via a set of gears and pinions

to multiply the torque. This bullwheel's rotational motion opens and closes the gate leaf perfectly. In fact, this geared

system supported the operation of the Panama locks for 84 years. After that, they were replaced by hydraulic

cylinders, making the locks more simple and efficient. Another great challenge the American engineers faced was the tremendous weight of these steel gates.

Look at these poor hinges; they have to withstand the heavy weight of the miter locks. The most efficient solution was

to design the gate with a hollow structure. The gates are always immersed in water. The hollow gate design generates buoyancy force and reduces the

force on the hinges, thus saving the hinges from premature failures. The mitered gates design successfully prevents water leakage

between the gates, but what about the leakage between the ground and gate? Da Vinci even had a solution for this

problem: place a step at the non-open region of the gate. Now please observe the movement of the gate cross-section.

Due to the same water force, the gates will almost be able to touch the step, and the leakage through the bottom of

the gate will be negligible. Have you ever noticed why the Panama Canal lock gates have narrow edges? The reason is

similar to this example: with the same applied force, the pressure multiplies at the narrow edges. This ensures better

material compression and a stronger watertight joint. Before you leave, please become a LeeX team member and enjoy our

Leonardo da Vinci's GENIUS invention - Miter Locks

Lesics  was founded by Sabin Mathew, an IIT Delhi post graduate in 2012. At Lesics, we aim to provide quality engineering education. Our videos are designed to clear misconceptions, create a passion for engineering and explain complicated technologies in a simple way.  

This channel is currenlty in the brink of a shutdown. Your support at Patreon is valuable to us : https://www.patreon.com/Lesics

Cheers Sabin

