Locomotive Ammonoosuc of the Mount Washington Cog Railway

Mechanical engineering applies the principles of physics and materials science for analysis, design, manufacturing, and maintenance of mechanical systems. Producing and using heat and mechanical power for machines and tools are the oldest examples of engineering.

Mechanical engineers research, design, manufacture, and test all kinds of mechanical things: tools, engines, machines, and other devices. They study materials, heat and energy transfer, manufacturing technologies, among other things to design machines and tools that will meet all the requirements for a particular job.

Mechanical engineers use physics principles of motion, energy and force as a basis for understanding, analyzing, designing, and building mechanical components and systems. Such systems could include bicycles, cars, engines, and solar energy systems. New human-related challenges could include robotically controlled artificial limbs and mechanical components for an artificial heart. Mechanical engineers often work for organizations such as Boeing, Intel, and Honeywell.

Core concepts include mechanics, kinematics, thermodynamics, materials science, structural analysis, and electricity. Mechanical engineers use these core principles along with tools like computer-aided engineering and product lifecycle management to design and analyze manufacturing plants, industrial equipment and machinery, heating and cooling systems, transport systems, aircraft, watercraft, robotics, medical devices, and others.

From the earliest days of the industrial revolution in Europe in the 18th century, the field has continually evolved to incorporate advancements in technology, composites, mechatronics, and nanotechnology.

Mechanical engineering overlaps with aerospace engineering, building services engineering, metallurgical engineering, marine engineering, civil engineering, electrical engineering, petroleum engineering, manufacturing engineering, and chemical engineering to varying amounts. Mechanical engineers also work in the field of Biomedical engineering, specifically with biomechanics, transport phenomena, biomechatronics, bionanotechnology and modeling of biological systems, like soft tissue mechanics.

Here is typical college Mechanical Engineering program (.pdf). Although programs vary, most include some or all of these basic engineering topics.

  • Applied Mechanics – Involved in the fundamental and applied field of mechanics, including solids, fluids and systems as well as the specialized areas of shock and vibration, transportation and computer applications.
  • Bioengineering – Deals with the application of mechanical engineering knowledge, skills and principles to the conception, design, development, analysis and operation of biomechanical systems.
  • Fluids Engineering – Involved in all areas of fluid mechanics, encompassing both fundamental as well as applications to all types of device, processes and machines involving fluid flow, including pumps, turbines, compressors, pipelines, fluidic systems, biological fluid elements and hydraulic structures.
  • Heat Transfer – Deals with the theory and application of heat transfer in equipment and thermodynamic processes in all fields of mechanical engineering and related technologies.
  • Materials –
  • Tribology – analysis of friction, wear, lubrication phenomena and the application of such principles to mechanical design, product development, manufacturing processes & machine operation.

Some related areas of specialization

  • mechanical design and fabrication, advanced manufacturing

Meet the people in Mechanical Engineering

  • Judy designs everything from children’s toys to pet products.

Trains can climb mountains
“The Cog”Mount Washington Cog Railway is the world’s first mountain-climbing cog railway (rack-and-pinion railway). The railway is still in operation, climbing Mount Washington in New Hampshire, USA. It uses a Marsh rack system and one or two steam locomotives and four biodiesel powered locomotives to carry tourists to the top of the mountain. The inventor and engineer, Sylvester Marsh, used the steps in the Engineering Design Process to solve the problem of transporting visitors up the mountain.

  • Ask – Sylvester Marsh (1803-1884), came up with the idea for the railway while climbing Mount Washington in 1857. The average grade is over 25% and a maximum grade is 37.41%. The railway is approximately 3 miles (4.8 km) long and ascends Mt. Washington’s western slope beginning at an elevation of approximately 2,700 feet (820 m) above sea level and ending just short of the mountain’s summit peak of 6,288 feet (1,917 m). What is the steepest grade for conventional railways? What limits the grade that a locomotive can climb?
  • Imagine – At the time, many people thought the design was attempting the impossible. What was Marsh going to do that was different?
  • Plan, Create – After developing a prototype locomotive and a short demonstration section of track, he found investors and started construction. How does this design differ from conventional designs? What prevents the train from sliding backwards? Each train consists of a locomotive pushing a single passenger car up the mountain, and descending the mountain by going backwards. Both locomotive and car were originally equipped with a ratchet and pawl mechanism engaged during the climb that prevents any roll-back; during descent, both locomotive and car are braked. How were the locomotives manufactured? What accommodations were made to a conventional steam boiler?
  • Improve – The new locomotives have a computer package on board that serves both to govern the engine and to monitor the engine’s exact position on the track. Biodiesel is a major source of energy. What improvements have been made? Why were these necessary?

That’s engineering

  • ratchet – a mechanical device that allows continuous linear or rotary motion in only one direction while preventing motion in the opposite direction.

Engineering ideas

  • physics, materials, analysis, design, manufacturing, mechanical systems, mechanics, kinematics, thermodynamics, materials science, structural analysis, electricity, ratchet

Do it
Here are some challenges for you to work on…

  • investigate 3-5 mechanical engineering specialties
  • build a model mechanical system that uses heat
  • Monster Physics (interactive simulation, app, free (lite)) – comes with 50 missions to solve including simple tutorials as well as mind-bending challenges. Many of the missions are open-ended and can be solved with a wide variety of different solutions

Learn more…

  • The CogMount Washington Cog Railway – the World’s First Mountain Climbing Train, the only Cog Railway East of the Rockies, to the Top of Mount Washington – the Highest Peak in New England
  • Rachet
  • Mechanical Engineering Textbooks – free engineering textbooks for mechanical engineers in computational fluid dynamics, heat transfer, control engineering, automation and robotics engineering