Last year I was contacted by the Philadelphia Section papers chairman of the American Society of Mechanical Engineers, who asked if I could make a presentation at a joint ASME, SNAME, SAME section meeting in Philadelphia on January 24, 2017.
I told him that, in principle, I would love to do that, but wondered what subject he was interested in. He thought that a presentation on cruise ship power plants might be of interest to the membership of the various societies that might be attending.
In our quick discussion I mentioned that this subject is a book size subject and what part of it would be of interest, and he indicated that a more general discussion would be fun. Without thinking about it much further I agreed, but after putting down the phone I became a little worried. read more »
When we talk about efficiencies it often becomes difficult to figure out who benefits from the efficiency. Airlines may be as efficient as they can be (spend the least amount on wages and fuel per passenger moved) but that does not mean that airline travel is efficient for the passengers. They may stand in long lines, be shunted through airports they do not want to visit and fly at times they do not want to fly. In other words, from the passenger’s point of view, each airline flight is often very inefficient.
Efficiency needs to be evaluated at a system level and the point of view needs to be defined. In 2009 David JC MacKay (1967-2016) wrote a wonderful book called “Sustainable Energy - without the Hot Air” and in that book he very carefully describes present day energy efficiencies and provides guidance on what efficiencies can be achieved. The book received very high praise and he was appointed Chief Scientific Advisor to the UK Department of Energy and Climate Change. However, he made a very interesting error in his analysis.
It is always important to ask “why” about every detail in every design, since bad design imposes a penalty on every user for the life of the bad design.
Bad design can hang around forever even if good design exists. I often ask “why?” when I am forced to use a badly designed cleat on a boat when we have a near perfect design in the 100 year old Herreshoff cleat.
We don't come across enough of these "why's", but I came across a nice one a few days ago.
This is a Guest Blog by our U. Mich summer intern Sam Edwards.
I was handed off progress on Project 114 by a previous intern in the office. He had added in a feature to plot the sections of files that were input to the “Hydro2A” calc engine as well as started the design of a “Marine High School Research Vessel”, or MHSRV. My goal was to continue tinkering with Project 114 as well as to continue design on the MHSRV.
The Maxi Taxi concept describes the advantages of convoying in saving fuel during highway travel. Cars that closely follow each other can achieve impressive reductions in total air drag. Air drag is the leading overall drag component at higher speeds and therefore represents the lion’s share of a car’s fuel consumption at speed.
Air drag is a complex subject, and the original maxi taxi concept aimed to reduce overall air drag by fitting a number of cars as close together as possible and thereby to create a drag profile that is similar to a railroad train, which is basically a flexible tube that is being dragged through the air. We can achieve a similar effect with car convoys and the cars do not have to be the same, but equal width would be real a benefit.
Project 114 is an innovative approach to engineering computations that is being developed for SNAME by Steve Hollister. In essence, it will be a suit of basic NAME computer programs that run on an Excel input/output backbone. This approach is quite powerful and runs a careful middle ground between large, canned, NAME program suites and home grown NAME computer programming. This effort is not meant to displace large powerful computational packages, but rather is meant to provide tools for occasional users and to allow a useful and standardized entry point for NAME amateurs, students and occasional users.
The project is further described at the SNAME website and at present a hydrostatics, a Savitsky and a basic powering module are available for experimentation. (beta testing?)
In March we were contacted by Monmouth County's High Technology High School and asked if we could place a student for the Spring. High Tech High School is one of the Monmouth County Vocational High Schools with which M&O has a steady interation and is one of the best technical high schools in the country.
High Tech wanted Brady Donahue to attend at our office for 3 months of Fridays since he had expressed an interest in vehicle design. Fortunately we had the perfect job for him; to be the first true student guinea pig for Project 114. read more »
M&O has worked on both the implementation and the failure analysis on quite a number of SWATH (Small Waterplane Area Twin Hull) projects in the last decades. SWATH vessels hold great promise and continue to intrigue naval architects and potential ship purchasers. When we first became involved in SWATHs, as far back as 1981 with the Monoform concept, SWATHs were described as: “The best solution for small ships in big waves”.
That truism has not changed, but it is clear that not all small ships in big waves are SWATHs today, and so how can that statement be true?
The truth of the statement is related to the disconnect between physics and design. Anything can be most efficient for any one condition, but that does not mean that it will be most efficient once it is turned into a real life object.
Life is complicated, and designing to deal with life’s complications is difficult. Unfortunately bad design unnecessarily punishes humanity by increasing inefficiencies and frustrations. Design mistakes get made, and sometimes the mistakes cannot be easily corrected. However, it is difficult to imagine anything more destructive to humanity than bad design that affects many people that can be easily corrected, but is not, due to mental laziness by those in charge. This story is about a sign.
On Easter I visited Hoover Dam. Earlier that week we had visited some of the great National Parks in the area and marveled at the skill of the National Park Service in designing and redesigning access to some of the most striking places in the world. Knowing that the Hoover Dam, like the National Parks, falls under the Department of the Interior, I was disappointed to note that the Bureau of Reclamation does not lean into the problem like the NPS.
True or not, this joke is attributed to Abraham Lincoln:
A farmer’s young son comes running into the house.
Out of breath he says: “Pa, Pa, the hired hand and Sis are in the hayloft. The hired hand has dropped his pants and Sis has pulled up her skirt! Pa, I think they are fixin’ to pee on the hay.”
The farmer says: “Son your facts are correct, but your conclusion is all wrong.”
A Time magazine article by Leigh Gallagher highlights a problem that we deal with on a daily basis but that pretty much stays just below our awareness horizon. In the article Mr. Gallagher describes a professional epiphany of a town engineer with regard to town planning codes that exhibits itself as suburban sprawl.
The issue is simple; every piece of infrastructure that is built to support a community needs to be maintained. Infrastructure on a large flat scale, as is common in suburbs, inherently is larger per capita than in more compactly arranged communities and therefore more expensive to maintain. (Maritime, on the other hand, only incurs terminal infrastructure investment and maintenance costs. The maritime highway infrastructure is essentially free). The article describes how this sprawl results in unmanageable infrastructure maintenance costs, but the solution is all around us.