Eiffel Tower

The structure of the Eiffel Tower weighs 7,300 tons. Depending on the ambient warmth the top of the tower may shift away from the sun by up to 18 cm (7 in) due to thermal growth of the metal on the side facing the sun. The tower also sways 6-7 cm (2-3 in) in the wind.

The first and second levels are reachable by stairs and lifts. A ticket booth at the south tower base sells tickets to use the stairs which begin at that position. At the first platform the stairs continue up from the east tower and the third level summit is only reachable by lift. Once you are on the first or second platform the stairs are open for anyone to climb or descend apart from of whether you have purchased a lift ticket or stair ticket. The actual count of stairs includes 9 steps to the ticket booth at the base, 328 steps to the first level, 340 steps to the second level and 18 steps to the lift platform on the second level. When exiting the lift at the third level 15 more steps exist to ascend to the upper inspection platform. The step count is printed sporadically on the side of the stairs to give an suggestion of progress. The majority of the ascent allows for an unhindered view of the area directly lower than and around the tower except during brief stretches of the stairway that are enclosed.
Maintenance of the tower includes applying 50 to 60 tons of paint every seven years to protect it from rust. In order to maintain a uniform exterior to an observer on the ground, three separate tones of paint are used on the tower, with the darkest tone on the bottom, and the lightest at the top. On occurrence the colour of the paint is changed — the tower is currently painted a shade of brownish-grey. On the first floor there are interactive consoles hosting a ballot for the colour to use for a future session of painting. The co-architects of the Eiffel Tower are Emile Nouguier, Maurice Koechlin and Stephen Sauvestre.

A diesel engine

In mechanical terms, the inside construction of a diesel engine is similar to its gasoline counterpart—components such as pistons, connecting rods and a crankshaft are current in both. Like a gasoline engine, a diesel engine may operate on a four-stroke cycle, or a two-stroke cycle, although with significant discrepancy to the gasoline comparable. In both cases, the principal differences lie in the handling of air and fuel, and the method of detonation.

A diesel engine relies upon density detonation to burn its fuel, instead of the spark plug used in a gasoline engine. If air is compressed to a high degree, its temperature will amplify to a point where fuel will burn upon contact. This principle is used in both four-stroke and two-stroke diesel engines to produce power.

Unlike a gasoline engine, which draws an air/fuel mixture into the cylinder during the ingestion stroke, the diesel aspirates air alone. Following ingestion, the cylinder is sealed and the air charge is highly compressed to heat it to the temperature required for ignition. Whereas a gasoline engine's compression ratio is rarely greater than 11:1 to avoid damaging preignition, a diesel's compression ratio is usually between 16:1 and 25:1. This extremely high level of compression causes the air temperature to increase to 700 to 900 degrees Celsius. If a piece of steel were to be heated to that level it would glow cherry red.

As the piston approaches top dead center, coal oil is injected into the cylinder at high pressure, causing the fuel charge to be atomized. Remaining to the high air temperature in the cylinder, detonation instantly occurs, causing a rapid and considerable increase in cylinder temperature and pressure. The piston is driven downward with great force, pushing on the connecting rod and turning the crankshaft.

When the piston nears bottom dead center the spent ignition gases are excluded from the cylinder to prepare for the next cycle. In many cases, the exhaust gases will be used to drive a turbocharger, which will increase the volume of the intake air charge, resulting in cleaner ignition and greater competence.