Writing Evaluation (Practice Version)

 

1.     Write a short (single paragraph) mechanism description for the tool shown below. Follow the guidelines discussed in class for mechanism descriptions.

 

 

 

 

 

 

 

 

 

 

Introductory lines

• Definition and purpose
• Overall description (with reference to visual)
• Principle of operation
• List of major components

 

Parts descriptions

• Definition
• Shape, dimensions, material
• (Subparts)
• Function and relation to adjoining parts

2. Write a summary of the following text. (Aim for approx. 150 words.)

Effects of the Disaster: Ship Design and Safety Regulations

 

In an effort to prevent repeating their mistakes, the White Star Line modified several of their existing ships following the Titanic disaster. The changes were based on the design flaws that were assumed to have contributed to the disaster. Along with these design changes, the White Star Line, and all shipbuilding companies at the time, had newly established safety regulations, agreed upon by both the British and American governments, that they had to follow. Developing safety regulations for ships at sea was another attempt to avoid accidents similar to the Titanic. The following is a discussion of the changes made in the design of ships and the safety regulations implemented as a result of the Titanic disaster.

Ship Design

Following the Titanic disaster, the White Star Line modified the design of the Titanic’s sister ships in two ways: the double bottoms were extended up the sides of the hull and the transverse bulkheads of the watertight compartments were raised. The double bottom on ships is constructed by taking two layers of steel that span the length of the ship and separating them by five feet of space [Garzke and others, 1994]. When a ship runs aground or strikes something in the water, the bottom plate of the hull can be punctured without damage incurred to the top plate. With a double bottom, the chance that a punctured hull would allow water into the watertight compartments is minimized. By extending the double bottoms up the sides of the hull, which adds another layer of steel to the sides of the ship, a similar event can be prevented. If an iceberg, or a collision with another ship, barely punctures the hull, only the space between the inner and outer sidewalls would flood with water. The watertight compartments would remain undamaged.

The ends of the transverse bulkheads of the watertight compartments were raised to prevent a tragedy similar to the Titanic. When the hull of the Titanic was torn open in the collision with the iceberg, water began to flood the damaged compartments in the bow. As the ship pitched forward under the weight of the water in the bow compartments, water began to spill over the tops of the bulkheads into adjacent, undamaged compartments. Although called watertight, the watertight compartments were actually only watertight horizontally; their tops were open and the walls extended only a few feet above the waterline. By raising the ends of the transverse bulkheads, if a ship were taking in water through the bow compartments and the ship began to pitch forward, the water in the compartments could not flow over the tops of the bulkheads into the next compartments. As a result, flooding of the damaged compartments could be controlled and isolated to only the damaged sections [Gannon, 1995].

At the 1948 Convention on Safety of Life at Sea, specifications for the orientation, length, and number of watertight compartments in passenger ships were established. The watertight compartments, which improve a ship’s ability to withstand the effects of underwater damage, are used to control flooding in the hull of the ship. To maintain a nearly level position, the walls of the watertight compartments are to be oriented horizontally, or across the width of the ship, rather than vertically. If one side of the hull is damaged, the water that fills the hull will even out across the width of the ship. With vertical walls, the water in the hull would remain on the damaged side of the ship, causing the ship to lean to that side. The length of the watertight compartments is determined by the length of the ship. Shorter ships should have shorter compartments while longer ships should have longer compartments. The number of compartments is also determined by the size of the ship. One criterion that must be met, however, is that the ship must remain afloat with two of the watertight compartments flooded [Muckle, 1951].

Safety Regulations

Along with the changes in ship design that resulted from the Titanic disaster, safety regulations were established to govern passenger ships while at sea. Many of these regulations were established at the 1948 Convention on Safety of Life at Sea. The mandatory use of the wireless, the increased lifeboat capacity, and the implementation of the ice patrol-each of these was developed to prevent accidents similar to the sinking of the Titanic [Garzke and others, 1994]. Wireless is the means of communication for ships at sea. The regulations require that ships exceeding 1600 tons be equipped with wireless apparatus. Use of the wireless is beneficial for ships because they are able to receive weather reports, check their positions, and call for help in emergencies [Society, 1977]. On the night of the Titanic disaster, several warnings were called in to the Titanic from ships aware of her position. Following her collision with the iceberg, the Titanic was able to send out distress signals to other ships with her position and the status of her damage, so help was on the way immediately.

Although there was room on deck for twice as many lifeboats, the Titanic carried lifeboats for just over half of the passengers and crew on board. The designer of the Titanic had allowed room on deck for two rows of lifeboats, but one row was removed before the voyage began to make the deck more aesthetically pleasing [Rogers and others, 1998]. With outdated British Board of Trade regulations, the Titanic’s twenty lifeboats actually exceeded requirements by 10 percent capacity [Refrigerator, 1998]. The new safety regulations increased the required number of lifeboats to a number that would accommodate all passengers and crew aboard the ship. Based on the length of the ship, a given number of davits, which are the mechanism used to raise and lower the lifeboats, are mounted along the perimeter of the lower deck. Figure 4 shows the davits and lifeboats on the deck of the Titanic. If the minimum lifeboat capacity is not met, additional lifeboats must be stowed under other boats. Regulations also specify that each of the lifeboats must carry oars, sails, a compass, signalling devices, food, and water. In addition, for large ships, two of the boats need to be motorboats [Manning, 1956].

The United States Government began the ice patrol so that ships travelling between England and the United States could be alerted of approaching ice fields. The ice patrol studies and observes the ice conditions in the North Atlantic in order to keep track of where the ice fields are in relation to nearby ships [Society, 1977]. Ice fields, large expanses of floating ice that are more than five miles in their greatest dimension, shift around depending on weather conditions. Therefore, without the ice patrol, ships would need to constantly monitor the positions of the ice fields. For the Titanic, the ice patrol could have informed the captain of the ice fields and surrounding icebergs and instructed him to stop the ship until morning.

(Adapted from Penn State University’s Writing Guidelines for Engineering and Science.

URL: http://writing.engr.psu.edu/workbooks/reports.html)

 

 

 

• Does the summary contain only the essential ideas?
• Have all author comments, conjectures, long explanations, examples, long definitions, and visuals been removed?
• Is the summary written with a level of technicality appropriate for the reader?
• Is the summary “stand alone” or “independent” in meaning?
• Is the summary free of personal assessment? (e.g., “This interesting article on…”)
• Has all unnecessary wording been removed?

 

 

Effects of the Disaster: Ship Design and Safety Regulations

 

White Star Line modified existing ships following the Titanic disaster to fix design flaws. They also established new safety regulations agreed upon by British and American governments.

 

Ship Design

White Star Line extended “double bottoms” up the sides of the hull to minimize risks of water entering watertight compartments after punctures. In addition, transverse bulkheads were raised to prevent water spilling over as damaged ships pitched forward.

 

The 1948 Convention on Safety of Life at Sea set new specifications for the orientation, length, and number of watertight compartments in passenger ships. Compartments were to be oriented horizontally so water would spread across the width of the ships to prevent leaning.

 

Safety Regulations

New safety regulations demanded

• mandatory use of wireless for communication between ships at sea;
• increased lifeboat capacity to accommodate all passengers and crew aboard a ship;
• implementation of an ice patrol to monitor ice conditions in the North Atlantic.

 

 

 

 

3. Write assembly instructions to accompany the steps shown in the visual shown below. Include introductory and background information, assembly steps (in brief but adequate detail), and suitable warnings.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Checklist for writing instructions:

Is the title clear and limiting? (e.g., Assembly Instructions for …)

Intro

• Has the purpose of the document been clearly stated?
• Have and prerequisite principles or requirements been stated?
• Have the steps you will discuss been listed?

Steps

• Is only the essential information provided?
• Have obvious steps been omitted? (e.g., Pick up the screwdriver in your hand.)
• Have you focused on the task and not the product? (“How do I use it?” and not, “How does it work?”)
• Has the text been adapted for reader knowledge and background?
• Do visuals reinforce the text?
• Do all actions required show parallel grammatical structure (likely starting with a verb)?
• Have appropriate dangers, warnings, cautions, or notes been included?

 

Conclusion

• Is the procedure summarized (in a line)?
• Have you stated where to find additional information (if applicable)?