At the lower levels of engineering responsibility, for example, the engineer may be assigned to work with surveyors in the precise layout of facilities during construction. On the other hand, a junior engineer may be engaged in the development of a small portion of the plans or designs for the construction of a major facility. A beginning designer may be assigned the task to select the most economical materials to use in a particular phase of a construction project. During the course of a design effort, the junior engineer may be assigned the task to calculate the quantities of materials and labor involved in a particular design and to estimate the cost to carry out that design. In general, for the engineer with little experience, the degree of responsibility assigned will be minor. Usually the junior engineer is assigned to accomplish a small part of a large task or all of a relatively minor design or plan.
The particular tasks to which the engineer is assigned will vary also with the area in which the engineer is specializing. For example, a structural engineer will work to estimate or determine the loads to which a structure will be exposed. In estimating these loads, the engineer will calculate the weight of all the building materials as well as the weight of snow which could accumulate on the roof of the finished building. He or she will also make an attempt to calculate the weight of all the people and equipment which could be placed inside the building at any time. He or she also must consider the effect of wind loads on the sides and top of the building as well as other forces such as earthquake forces. After determining all of the various loads which could be placed on the building, he or she must calculate the corresponding forces which are created in all of the members of the building structure. In making this calculation, a considerable amount of judgment must be exercised concerning the probabilities of the loads actually being present at the same time on the structure. In other words, he or she will have to decide if it is probable that a maximum snow load will exist on a roof of a building at the same time that high-velocity winds strike the sides of the building. The engineer will have to decide if earthquake forces should be combined with wind load and snow load in the design. This decision will require a considerable amount of experience, and usually only senior level engineers will make this sort of judgment. After the structural engineer has developed a combination of forces which he or she considers most appropriate for a particular building, he or she will have to select the most efficient combination of materials and structural shapes to carry the loading.
For example, in Hawaii, engineers built a highway from Pearl Harbor to the Kanohe Marine Air Corps Base on the other side of the island. The highway ran some fifteen miles through a protected habitat-a rainforest that's a national landmark. What's more, they had to drill a tunnel through the island's oldest volcano. Their challenge: build a strategic highway but do it so the environmental harm was minimized.
As another example, the civil engineer may build a new water system crucial to a city's supply of fresh water. In Chicago, engineers built a series of waterfalls to add oxygen to stagnant water in a $40 million side stream elevated pool aeration project that cost the city hundreds of millions of dollars less than it would have cost to build advanced water treatment plants. Some 260 million gallons a day now flow over four waterfalls on Chicago's south side, reported Civil Engineering magazine in July 1995.
The water resources engineer in a typical project would be required to estimate the demand by a community for water supplies and for facilities to carry away and treat waste waters. A junior engineer could be employed in estimating these quantities. A more senior engineer usually would be in charge of designing the actual facilities for treatment of water and water distribution. A senior engineer also would be in charge of the design and planning of a sewer system or a wastewater treatment plant. Usually, engineers with little experience would be assigned only small portions of the overall design responsibility.
