Monday, September 24, 2007

Appendices & Images

Oarlock Sketches*







Fig 4- Wood thole Oarlock Fig 5- Wood Pin Oarlock







Fig 6- Standard Oarlock Fig 7- Round Oarlock







Fig 8- North River Oarlock Fig 9- "Ram" Style Oarlock






*Sketches credited in Works Cited










Vessel Restoration






Fig 10- Vessel in Original Condition Fig 11- Results of Powerwashing








Fig 12- Fiberglass Repair Fig 13- Oarlock Repair






Fig 14- Oarlock Hole Repair Fig 15- Ideal Oarlock




Design Inspiration*



Fig 16- Frog Hook Fig 17- Sailboat T-Track

*Images credited in works cited

Test Procedures

Testing Procedures


The oarlock prototype will be fitted to the test dinghy, so it is quite possible to actually test the prototype in the environment that it would exist in a real life situation. Oars can be fitted to the locks and adjusted to the tester’s specifications. The vessel will be placed in a suitable amount of water, and the tester will attempt a rowing action using the adjustable oarlocks. If the product performs without breaking or otherwise compromising the overall abilities of the prototype, then the design brief will have met with the specifications. The adjustable oarlocks can be removed and tested against the normal set, and if it is indeed easier to row with the adjustable set over the original set, then it can be determined that the project was a success.

Vessel in which testing will take place.


Testing Procedures Listed

1. Oars fitting to testing mechanism
2. Oars adjusted to tester’s preferred setting
3. Boat placed in water
4. Oars used to propel boat in testing water
5. Oars adjusted in mechanism during test
6. Boat removed from water
7. Oars removed from testing block
8. Testing block removed from vessel
9. Testing block inspected for damage
10. Vessel inspected for damage

Calender: Marking Period One

9/17/07- Create Web Log

9/18/07- Add:
-Background Information
-Design Brief
-Testing Procedures
-Specifications & Limitations

9/19/07- Add Summer Research, Works Cited

9/20/07- Finish Calendar for Marking Period 1

9/21/07- Add Brainstorming, Alternate Solutions

9/22/07- Add Testing Procedures

9/23/07- Add Appendices:
-Photographs (Restoration of Boat)
-Sketches (Oarlock Designs)
-AutoCAD Drawings (Three Alternate Solutions)

9/25/07-Add Selection/Rejection Report

9/29/07- Visit Mentor (Visit #1)

9/30/07-10/2/07- Prepare Web Log for Informal Presentation

10/3/07- Informal Progress Update

10/6/07- Visit Mentor (Visit #2)

10/7/07-10/14/07- Creation of Model

10/13/07- Visit Mentor (Visit #3)

10/20/07- Visit Mentor (Visit #4)

10/21/07-10/30/07- Prepare Web Log for Formal Presentation

10/31/07- Mentor Contacts Required, Model & Selection/Rejection Reports Required

11/1/07- Formal Updates Begin- Outline Required

11/13/07- Marking Period Ends

Friday, September 21, 2007

Alternate Solutions

Alternate Solutions

Design One- Wood and Metal Hybrid
This iteration of design has been created to provide for a model which boasts fast production with the use of available materials. Wood is easy to work with when compared with other mediums, such as steel or fiberglass, and can be modeled into a variety of shapes to suit an individual requirement. With all of the positive traits attributed to wood, there is one major negative: structural integrity. Wood is somewhat flimsy when compared to metals, and even hard wood can crack under pressure. This design incorporates metal into a wood dominant design, reinforcing the product at several key points. Each hole, tapped to provide a space for the oarlock, is lined with metal, to protect against friction and other wear normally associated with a rowing action. A stainless steel bolt, part of each design offered, is tapped directly through the entire wood block, at its exact center. This bolt will travel through the existing oarlock socket and be secured with a locking washer and nut, firmly seating the block in place. The washer and nut can be removed at any time, without resulting in damage to the vessel or the adjustable oarlock block.

Design Two- Angle Iron
The second design presented is more conventional, using an entirely metallic structure to ensure lasting integrity for the life of the product. This design is more difficult to construct then a wooden hybrid, requiring the use of solder, and possibly light welding. However, the tradeoff of the more complex design is a lighter, more durable mechanism which is more resistant to both the actions of the marine environment and repeated, heavy use. The two pieces of angle iron are supplemented by metal tubes, used to sheath the oarlock pegs. Free space below the tubing allows for the insertion of a small cotter pin, which can ensure that oarlock cannot come loose during operation. The wooden block cannot offer this functionality; as such a space would compromise the entire block’s integrity. The stainless steel bolt works in the same manner as the wooden block, but can safely be positioned towards the bottom of the block without sacrificing stability. A washer, placed underneath the bolt’s head, ensures firm and constant pressure to lock the adjustable block onto the vessel’s existing apparatus.

Design Three- Sailboat T-Track Modification
The final design is the most ambitious of the three proposed models. This rendition involves taking existing technology, namely, a sailboat rail track, and adapting it into use for the adjustable oarlock. The sailboat track uses a ratcheting system in order to move line, which in turns adjusts the sail. This technology can be adjusted easily, without tools, which lends itself to modification for the purposes of this design project. A base of angle iron can secure the sailboat track in position about the original oarlock socket, keeping a low center of gravity which will reduce twisting and other undesirable movement of the adjustable oarlock block. Since the hardware is already available, the design process will concentrate on creating an object that can move effortlessly along the existing rails.

Brainstorming

Brainstorming
Vessel Restoration
Before design was attempted on the adjustable oarlock block itself, the boat which would serve as the test vessel required several repairs and alterations in order to become seaworthy. This phase of the project was crucial, as the effectiveness of the repairs would determine the dinghy’s ability to properly test the model. The design of the test boat would provide several details for the construction of the adjustable oarlock block. Although the block will be designed to function regardless of make or model, the model will be especially well suited to the test model, as the dimensions will taken from the existing oarlock sockets of this model in particular.
The vessel was provided free of charge by Fair Haven Yacht Works. The dinghy had laid along a wall for two decades, overgrown with weeds and covered in accumulated dust. A quick survey of the exterior revealed a small hole in the fiberglass hull, which could potentially compromise hull stability. Aside from minor cosmetic spider cracking and the aforementioned grime, the vessel seemed to be in serviceable condition, at least for the needs of the project. Once removed from the wall, a closer inspection revealed faded a registration tag on the left side of the bow, revealing the boat to have originated in New York state. A sticker on the right section of the stern proclaimed the boat to be a product of “Skimmar Aeronautical.” A search of iBoats.com, using the make and approximate dimensions, reveals the vessel to be a mid-to-late 1970’s “Scalawag.” The “Scalawag” model has appropriate equipment to be rigged as a sailboat, but can be adapted for a variety of uses (iBoats.com). Standard oarlocks enable quick conversion into a rowboat, and provided motor mount permits the use of a small outboard engine. On the test dinghy, oarlocks on the starboard side had been replaced and refitted, presumably due to some damage in the vessel’s history. The wooden motor mount had long since rotted away, destroyed by the passage of twenty years. Clearly, however stable the boat appeared, work was required in order to provide for the fitting of an adjustable oarlock block.
The original state of the vessel (Fig. 10) demonstrates the condition as received. Within days, supplies were gathered in order to affect repairs on the boat. The original rub rail was removed, as dry rot had rendered it useless. The hull was then powerwashed, to remove the set-in grit and grime that had sunken deep into the outer gelcoat. The hull cleaned up quickly, and the difference was quite noticeable (Fig. 11). After drying, the vessel was flipped upside-down and fiberglass repairs were affected to the rotted areas. Epoxy resin was applied to the bottom of the vessel, (Fig. 12) sealing the area entirely. Once dry, the process was repeated on the oarlocks which had been earlier replaced, to better seal them against the elements (Fig. 13). Another oarlock, on the port side, was filled in with marine-grade sealant (Fig. 14), in order to match the final oarlock, still in ideal condition (Fig. 15). At the same time, a large cut of maple wood was stained and sealed, in preparation for addition as a bench seat, while a smaller piece was prepared to serve as the new motor mount. At this stage, a great deal of work had been done to the vessel, and attention was turned to design of the adjustable oarlock itself.

Adjustable Oarlock Design- Design Problems
The design for the actual mechanism which would adjust the oarlock has several key design problems which must be addressed for construction can commence. The ideal design would incorporate elements which would allow for complete, detailed control over the adjustment of oarlock position. However, this presents a problem, as detailed control requires precision which may not be possible to create with the tools provided in the Systems Engineering workshop. . Full control can be attempted with the adaptation of existing materials, used for other purposes. An example of this adaptation uses sailboat T-rails, which are currently used to provide mobile points for the movement of sails (Fig. 16). It is possible that these devices can be retrofitted to hold a set of oarlocks, enabling them to be adjusted to any conceivable position cut into the T-rail. A suitable alternative to complete control over adjustments may be to provide a wide range of pre-determined positions for the oarlocks to fasten into, but stop short of allowing full adjustment. This compromise allows for the device to fulfill its design requirements and remain relatively easy to produce. A system which uses holes tapped through sturdy angle iron may be the easiest example of such a device, although other possibilities exist. A series of metal tubes, each one carefully soldered into place on a set of angle iron, would prove more stable, and require minimal effort to design and create.
Another design issue the production of such a device remains the composition of its component parts. Original design specs suggested that the device should use a hard wood, for it is commonly available and relatively cheap. After suitable appraisal of this design, it has become clear that wood alone will not be strong enough to withstand the rigors of repeated use. In the event of failure, a wooden mechanism would simply splinter apart, leaving little hope for repair, if any. Standard, non-adjustable oarlocks have to contend with a great deal of friction wear, which could render a wooden design useless in a short period of time. A mechanism that relies upon metal seems to make a great deal of sense, considering the associated wear and tear of the marine environment. If large quantities of metal are not available, it is possible to design a product that does use wood, reinforced by metal inserts in order to prevent the accelerated wear that is associated with the use of wood.
The final major design problem rests with the use of tools for adjustment. It is difficult to adjust nuts, bolts and screws to their tightest position without the use of tools. The universal mounting design calls for the use of a suitable bolt and nut assembly, with the nut tightened to lock the adjustable oarlock block in place. In order to assure that this nut is securely fastened at all times, it is imperative that it not be loose. It is difficult to tighten a nut without a small wrench of correct size, but these tools are easily lost on boats, either overboard, or lost to the harsh marine environment. This hardware problem can be solved in many ways, for little or not appreciable cost. The addition of a washer and wing-nut can mean that the nut can be adjusted tightly without the use of tools, and the washer ensures that even pressure will hold the entire assembly in place. If this design is not viable, a small wrench could be incorporated into the design, with the addition of a lanyard. This lanyard would secure the wrench to the assembly, preventing its loss overboard, and ensuring that the assembly can be removed at any time the user wishes.

Thursday, September 20, 2007

Works Cited

Works Cited
"Biometrics." The American Heritage® New Dictionary of Cultural Literacy, Third Edition.
Houghton Mifflin Company, 2005. 25 July 2007. http://dictionary.reference.com/browse/biometrics.


Culler, R.D. Boats, Oars and Rowing.
International Marine Publishing Company: Maine, 1978.


"General Information Concerning Patents." Jan. 2005.
United States Patent and Trademark Office. 20 July 2007.
http://www.uspto.gov/web/offices/pac/doc/general/index.html.

"Innovation." The American Heritage® Dictionary of the English Language, Fourth Edition.
Houghton Mifflin Company, 2004. 26 July 2007.
http://dictionary.reference.com/browse/innovation.

“Invention." The American Heritage® Dictionary of the English Language, Fourth Edition.
Houghton Mifflin Company, 2004. 28 July 2007. http://dictionary.reference.com/browse/invention.

Lavery, Brian. Ship: The Epic Story of Maritime Adventure.
DK Publishing Inc: New York, 2004.

"Skimmar Scalwag-S." iBoats.Com. 20 July 2007
http://www.iboats.com/Skimmar__Scalawag-S__1976/bp/64b158620r1

Works Cited- Images

Culler, R.D. Wood Pin Design Oarlock. Boats, Oars & Rowing. By R.D. Culler.
Camden, Maine: International Marine Publishing Company, 1978.

Culler, R.D. Wood Thole Oarlock. Boats, Oars & Rowing. By R.D. Culler.
Camden, Maine: International Marine Publishing Company, 1978.

Culler, R.D. Standard Socket Oarlock. Boats, Oars & Rowing. By R.D. Culler.
Camden, Maine: International Marine Publishing Company, 1978.

Culler, R.D. Round Oarlock. Boats, Oars & Rowing. By R.D. Culler.
Camden, Maine: International Marine Publishing Company, 1978.

Culler, R.D. North River Oarlock. Boats, Oars & Rowing. By R.D. Culler.
Camden, Maine: International Marine Publishing Company, 1978.

Culler, R.D. Ram Style Oarlock. Boats, Oars & Rowing. By R.D. Culler.
Camden, Maine: International Marine Publishing Company, 1978.

Performance Yacht.com. Round Oarlock
http://pyacht.net/online-store/graphics/PER_Rd_Oarlock.gif

Row2K Media. Magik Oarlock.
http://www.row2k.com/news/images/MagikOarlockDBC.jpg

West Marine. Stainless Steel Oarlock Socket.
http://images.westmarine.com/full/6820377.jpg

West Marine. Shaefer Racing T-Track.
http://images.westmarine.com/full/11004_f.jpg

Related Products & Design

Similar Products
Inspiration for design can be taken from existing marine equipment. “Frog Hooks,” metal arms which are used to secure boats, use a system of cotter pins and plastic lanyards to secure boats in place (Fig. 17-18). These principles can be transferred to the makeup of the adjustable oarlock block, as cotter pins are a cheap and effective way of securing material to marine equipment. The metal pins used to connect the stern of a vessel too the dock are semi-removable, but cannot be entirely removed without the use of tools. This allows the pins to remain in an accessible position without requiring great effort on the part of the user. This functionality can be of great use to the design of the adjustable oarlock, as metal pins can survive the conditions present in the marine environment, and the accessibility and ease of use greatly lend themselves to placement in a commercial product.

Oarlock Design- Lanyards
Oar locks, other than those attached to the oars, will require lanyards, as will tholes or pins as well. Some pins are totally fixed in some working craft, but this is apt to be unhandy and cause trouble, especially if you go alongside other craft or even a float or wharf. Lanyards are, of course, to prevent loss of the rowing gear overboard. There are many lanyards that consist just of a piece of any old twine or chain. The system of a piece of cod line connecting a pair of oarlocks and running one to the other across the boat is a poor thing, something to trip over. With tholes, the lanyard should go through the holes in the rail or block, to prevent chafing (Culler 87).

Materials Processing
This product requires several skills in order to create a working prototype, and eventually, a fully functional example. The design calls for that of metal, or a wood-metal mixture, so the ability to craft metal together is integral to the success of the project. Metal soldering is a must, as is simple metal cutting. If the final design does include wood, the designer must know how to correctly measure and cut pieces of raw lumber. Finishing this wood is also a mandatory skill, using either varnish or some other type of sealant. Testing the product requires a rudimentary knowledge of oars and rowing, as the device will not function as performed if the tester does not have the skills inherent in rowing a vessel.

Oarlock History

Oarlock Design- Original Conception
Just how far back men started rowing, and what their first gear was like, we don’t know for sure. It’s well known how boats were propelled in ancient times in the Mediterranean and in Norse waters; boats in both of these areas relied very much on oars (Culler 81). A relief from about 700 BC shows Phoenician galleys with very pointed, curved rams, single rows of oarsmen, curved sterns, and fighting decks with shields along their sides (Lavery 23). Less warlike vessels also appear in the relief, without rams but still propelled by oars and with a deck above, carrying distinguished looking passengers (Lavery 23). By about 600 BC, the Corinthians reached the next stage and built the famous trireme, with three levels of oars. The trireme was copied by the various city-states, such as Athens and Sparta, and by 500 BC it was the most successful warship in the eastern Mediterranean (Lavery 24).

Oarlock Design- Early Design
The early Norse way for holding the oar to the boat was a naturally grown chock ahead of the oar, with a hole and thong to help retain the oar. Other craft used a pin of wood for the oar to work against; this pin was usually mounted on a block, with a strop used to retain the oar (Fig. 1) (Culler 81). Another version was similar to an oarlock- two nicely shaped chocks of wood forming horns to retain the oar. (Fig. 2) There were many variations of the same principle, some removable and some adjustable (Culler 82). Thole pins are still in use, and many people are familiar with them. In the past some pins, notably those used in Europe, were often oblong in section, shaped on the inside to suit the oar, and fitted in sockets shaped to them in the rail. Some tholes used a fairly high chafing block if the boat was low, sometimes the forward pin was higher and stronger then the after one (Culler 83). Dory thole pins always used lanyards- all tholes should have lanyards- but there are few other absolutes in thole-pin design. There are many slight variations in the shapes of both the round and squarish-type tholes- some of this design work is very good, based as it is on what works and what does not (Culler 83).

Oarlock Design- Modern Changes
With the creation of new technology, demand for highly specialized oarlock hardware decreased rapidly. Many different patterns of oarlocks were discontinued. There were little or no sales of specialty locks, so the lines were dropped. Now only a minimal choice of types that still sell can be found (Culler 71). Stock patterns available now include a couple of models of side-mount sockets and flat mount sockets, some of these tapered, some not. (Fig 3) Also to be found are round-type locks that stay on the oar, using a leather “button” to keep them on. (Fig 4) The standard horned type is still available in ribbed or plan pattern, sometimes with a lanyard eye. Still available is the North River pattern, (Fig. 5) which is similar to the guideboat pattern. It features a pin through the horns and the oar itself, so the oar cannot be feathered. The North River usually uses a side-plate for mounting. That these work for the intended use, there is no doubt; they have much advantage [in] fishing, but for most rowing you want to feather the oars, and you can’t do it with these (Culler 73). There is still available the ram-type lock, (Fig. 6) with fixed horns on a plate. Many now will look with doubt on such a rig, but these oarlocks have stood the test of time- the principle of their use may go as far back as the use of oars. The ram-type lock is easy to mount stoutly; one pattern has been used in Jersey beach skiffs for years- very practical for the right boat (Culler 74). Materials for today’s oarlocks are now either galvanized iron or bronze, and most seem to be some sort of a drop forge or casting. In the past, bronze oarlocks were highly finished; some even were nickel plated. Now, for the stock ones, the story is different. They are very rough, and often, though they are supposed to be matched, they can be found either to be very slack or to bind in the sockets (Culler 74).

Wednesday, September 19, 2007

Design Brief Introduction

Design Brief:
This purpose of this project is to design an adjustable oarlock, capable of being fitted to a variety of existing vessels through their existing oarlock apparatus.

Specifications:
· Must be removable once fitted
· Must be capable of fitting to existing oarlock machinery
· Must be constructed of marine grade materials
· Must provide multiple positions for oarlock arrangement
· Must be solid enough to hold large, heavy oars
· Minimal tool requirements for removal, adjustment

Limitations:
Ø Not all oarlocks are same size and dimensions
Ø Fine adjustments difficult without use of tools
Ø Amount of adjustment dependant on size of fitting
Ø Materials must withstand extremes of marine environment
Ø Heavy use could damage mounting bracket on vessel
Ø Tools can become lost, damaged


Testing Procedures
The oarlock prototype will be fitted to the test dinghy, so it is quite possible to actually test the prototype in the environment that it would exist in a real life situation. Oars can be fitted to the locks and adjusted to the tester’s specifications. If the product performs without breaking or otherwise compromising the overall abilities of the prototype, then the design brief will have met with the specifications. The adjustable oarlocks can be removed and tested against the normal set, and if it is indeed easier to row with the adjustable set over the original set, then it can be determined that the project was a success.

Testing Procedures Listed
1. Oars fitting to testing mechanism
2. Oars adjusted to tester’s preferred setting
3. Boat placed in water
4. Oars used to propel boat in testing water
5. Oars adjusted in mechanism during test
6. Boat removed from water
7. Oars removed from testing block
8. Testing block removed from vessel
9. Testing block inspected for damage
10. Vessel inspected for damage

Background Information

Background Information:
Man has used boats to assist him since the beginning of earliest recorded history. Across the world, each civilization adopted its local resources to the water, but with such primitive craft, skill and luck were required to avoid danger (Lavery 11). A key part of this early construction involved the manner in which the boat would move across the water. A boat needs some means of propulsion. If conditions allow, it can be towed or it can be moved by punting- using a pole to push against the bed of the river- but a more effective and adaptable way is to paddle by hand or by using a pole with a flat surface at one end as a paddle. Facing in the direction of travel, the paddler leans forward or stands up, places his paddle as far forward in the water as he can, and then pulls it back toward himself, propelling the boat forward. Rowing is a more complex idea. Usually, the rower sits with his back facing the forward course of the vessel, and the oar is pivoted near its center. In Greek triremes, the oarsman stayed in his seat, directed the oars behind him, and leaned backward with the stroke, his feet braced against a bar. An oarsman uses his whole body in every stroke, not just his arms and back as in paddling, this propelling the vessel more quickly (Lavery 15).
The descendants of these ancient techniques: rowboats, portable dinghies, aluminum boats and their derivates have undergone many design changes throughout the years, but the technology for keeping the oars secure while rowing has not changed significantly, if at all. Oars are commonly held through a simple metal loop, such as seen in figure one. The oars are placed inside of these small hoops, and are securely fastened to the boat through the vessel’s oarlock fitting, shown in figure two. These fittings cannot move, and the oars can be hard to manage for smaller rowers, or cumbersome to row for larger people. Personal preference could demand the oars be placed further forward or backward, but even modern oarlocks make no concessions for adjustments.
This ancient technology that is provided with the most common rowboats and dinghies is not in keeping with the advanced locking systems used by many racing shells. As shown in figure three, these shells use highly advanced clamp systems to give the rowers a competitive edge in the sport. While this progress may help professional rowers and athletes, this amount of technology is not required on the personal dinghy. These clamp systems are designed to work on specific types of rowing sculls, and do not mount on standard rowboats. No appropriate device has yet been developed for the common rowboat, even though such an apparatus would have a wide market open to it.
The wide range of owners and operators who take advantage of the versatility and utility of rowboats requires boat designers to craft vessels which are comfortable for the greatest range of people. Creating a boat such as this means that those outside this range will have a reduced level of comfort, and as such, the accessibility of the design will be significantly reduced. With the addition of a product that increases the ease of use for a greater variety of people, these boat designs would become more popular to those who previously could not take full advantage of all that the vessel could offer.
An adjustable oarlock would provide a solution to the above problem, but the solution itself must overcome several problems. The oarlocks must be removable from the vessel’s hull, if the original fittings are required for any reason. The product must use marine grade materials, or the structural integrity of the mechanism will become compromised once exposed to the rigors of the marine environment. It is preferable that the design requires minimal use of tools, as these tools can become lost, preventing removal or further adjustment. Despite these limitations in design, such a device would greatly improve the performance of any craft suitably equipped.