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- Herausgeber: Edizioni Savine
- Kategorie: Wissenschaft und neue Technologien
- Sprache: Englisch
- Veröffentlichungsjahr: 2021
The fundamental principles and practical methods described in detail. Especially written for carpenters and other woodworkers who desire to engage in boat or ship building, and as a text-book for schools.
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A PRACTICAL COURSE
in WOODEN BOAT and
SHIP BUILDING
The Fundamental Principles and Practical Methods Described in Detail
Especially Written for Carpenters and Other Woodworkers Who Desire to Engage in Boat or Ship Building, and as a Text-book for Schools
By
RICHARD M. VAN GAASBEEK
Head of Department of Woodworking, School of Science and Technology, Pratt Institute, Brooklyn, N. Y.
FULLY ILLUSTRATED
Copyright, 1918, by Frederick J. Drake & Co., Chicago
New digital edition
© 2021 - Edizioni Savine
PREFACE
To meet a popular demand for a text-book to assist the great army of house carpenters and other woodworkers in transferring from their usual occupations to the wooden boat and ship building industries, now rapidly developing in this country, and especially for those men who wish to qualify for advanced positions, and for boat and ship builders who wish to broaden their experience in order that they may prepare for greater responsibilities, this work is offered.
The text is the outgrowth and development of a pioneer course organized early in the war by Pratt Institute, Brooklyn, N. Y., in response to the demand caused by shortage of skilled labor in these industries.
It was a study to know how to organize the work effectively, to select only those problems that otherwise might take years of labor in the industry for these men to solve, and to present the problems progressively and in such a way that the men would grasp the basic principles in the shortest possible time.
It has been the aim of the author to establish a fundamental course,—one that would help the ship builder as well as the boat builder; for whatever the size or type of the vessel, the general principles of construction remain very much the same in all cases.
Those who master this course can direct the labor of others, because they themselves will have learned by doing, and it is only by manipulative skill that a practical understanding of the subject can be acquired.
It was out of the question to build a full-size ship. The space and equipment necessary to handle heavy timbers, the cost of the lumber itself, and the extra labor that would be required of the men after a hard day’s work, were all factors to be considered in determining the kind of instruction that would best meet the emergency situation.
We have built a full-size boat, using full-size timbers, and under exact factory conditions, and with the scarfing and adzing of heavy yellow-pine timbers and practice calking, both light and heavy, a course has developed, which, judging from the reports from the men as to their advancement and success in the industry after completing the course, has been most gratifying.
The author has not attempted to give a complete treatise on the subject and therefore offers no apology for any omissions that may be found. The first part of the work (Chapters I to IV) is strictly technical in character, giving the operations in sequence as they were performed on the job and explaining them in such a way that the average mechanic can understand. In the second part (Chapters V to VIII) an effort is made to show typical ship construction views, giving the reader an idea of the methods of handling and fastening heavy timbers.
The author wishes to express his appreciation of the generous assistance given by Messrs. Chas. Rassiga, Jr., Edward J. Weber and Harvey R. Saylor, his co-workers, and to leading wooden ship builders and manufacturers, without whose aid this work would have been impossible.
Particularly the author wishes to acknowledge his indebtedness to Mr. W. G. Hudson, District Supervisor, Wood Hull Construction, Second District, Emergency Fleet Corporation; Mr. Theodore E. Perris; The Foundation Company, agents of the United States Shipping Board, Emergency Fleet Corporation; Messrs. Tams, Lemoine and Crane; Stetson Machine Works; Messrs. J. A. Fay
& Egan Company and Messrs. C. R. Durkee & Co. for permission to use the drawings and photographs used in illustrating the second part of the work.
The Author.
Pratt Institute,
Brooklyn, N. Y.
July 1, 1918.
CHAPTER I
THE MOULD LOFT
The principal drawing of a vessel is the sheer drawing. It is composed of three parts, mutually dependent upon each other, as follows:
Sheer Plan.—Figure 1.—A side view showing length of vessel and heights of sheer or gunwale.
Half-breadth Plan.—Figure 2.—A top view, showing a horizontal or floor plan on any water lines.
Body Plan.—Figure 3.—An end view, showing curves of the frame line's outside the timber at any point in the vessel. Frame lines forward of the midship section are on the right of the center line; aft of the midship section on the left of the center line.
TABLE OF OFFSETS
The table of offsets exhibits the distances from a center or base line. These offsets are compiled by the naval architect and are used by the mould loftsman in laying down the lines on the floor.
Just how these offsets are compiled is only of passing interest to the reader, as it is the purpose of this work to help the mechanic to apply them.
Model for Taking Off Offsets.—The most practical way of taking off the offsets is to make a model of wood, an invention of an American mechanic. The model must be made to an exact
scale, usually 1/4" to 1', and it is generally composed of two kinds of soft wood of different colors, such as pine and cedar, in alternate layers screwed or pinned together. The seams between the layers represent the water lines.
The model usually represents the starboard half of the vessel and has a plane side, representing the longitudinal midship plane, on which the sheer plan is drawn. Its curved side is then gradually carved, shaved, and filed to such a form as to satisfy the eye and the judgment of the designer.
It is very important, in making the model, to fair up perfectly every portion, so that one portion of it assimilates with the other. If the model is made to a small scale, the discrepancies can be more readily detected, because the whole of the model can be seen at a glance and the inequalities of one end as compared with the other will be discovered. The model must be perfectly fair, not only on all lines, but in every direction.
Station lines, rabbet line and bearding line, and all water lines are laid off to the same scale on the model. The layers can then be separated and from these the table of offsets is scaled. The accuracy with which the model is scaled will save the time of the mould loftsman in laying down his lines.
MOULD LOFT WORK
Laying Off of the Lines.—The laying off of the lines on the mould loft floor can be compared with the foreman’s layout in carpenter work. (See Figure 4.) It is the name given to the process of drawing the lines of a vessel to full size in plan and elevation, in order to determine the exact dimensions of the most important and fundamental parts of the structure. The necessity for drawing to full size arises from the extreme accuracy with which the dimensions of the various parts must correspond with one another in order that when assembled there may be no irregularity or unfairness in the surface of the vessel.
If the mould loft is not long enough for laying down the vessel full length, it can be laid down in
Figure 4.—Fairing-in a Line on Mould Loft Floor.
sections, one overlapping the other, providing the sections are long enough to properly fair up the lines. If the vessel is very large, this is an important operation, for while looking at one part of the line, it may be impossible to see the other side of the same line. Figure 4 shows a section of the
mould loft floor at Pratt Institute, Brooklyn, N. Y. The men are fairing-in a line, as can be seen; that is, making its curve true and regular. A mechanical eye will save a great deal of labor, for much depends upon the fairing-in of the lines, as considerable injury may be done to a good design by deviating from the drawings.
THE SHEER PLAN
To lay off the sheer plan, Figure 1, first produce the base line and run the water lines in parallel
to the base line. Then strike in the station lines at right angles to the base line and equidistant apart.
The method of laying down one or two lines will suffice to give the reader enough information to enable him to complete the layout. We will assume that the vessel has been outlined and will therefore lay off the sheer line and section 5.
To lay out the sheer line refer to top line of the table of offsets. This gives the heights of gunwale or sheer above the base line. Point off these distances on the various stations from the base line. The first figure represents feet, the second inches, and the third eighths, as follows :
At the stem, 2' 2" ; on station 1, 1' 11 6/8" ; station 2, 1' 5/8" ; station 3, 1' 7/8" ; station 4, 1' 6 5/8" ; station 5, 1' 5 7/8"; station 6, 1' 5 4/8"; station 7, 1' 5 4/8" ; station 8, 1' 5 6/8" ; station 9, 1' 6 1/8" ; station 10,1' 7" ; station 11,1' 8 1/8", and at the transom, 1' 9 6/8".
Drive a small nail in at these points and bend a thin batten so as to approximate as closely to these points as is consistent with absolute fairness and continuity. If the batten does not spring well to these points, it is best to pass the batten inside some and outside others in order to prevent great deviation from the design in either direction.
Likewise refer to section 5 on the sheer plan and height of section 5 above base in the table of offsets. Point off on each station line as shown, namely, station 2, 1' 7" ; station 3, 0' 9 1/8" ; station 4, 0' 5" ; station 5, 0' 3 2/8"; station 6, 0' 2 6/8"; station 7, 0' 2 6/8" ; station 8, 0' 3 4/8" ; station 9, 0' 5" ; station 10, 0' 8", and station 11, 1' 0 7/8". Drive a small nail in at these points and bend a thin batten through them as described in the preceding paragraph.
HALF-BREADTH PLAN
To lay off the half-breadth plan, Figure 2, strike a line representing the center line and mark in the stations of the frames as shown. Set up from the center line on the various stations the half-breadths of the water lines and sheer lines, taking the distance from the table of offsets.
The method of laying down the half-breadths of water line No. 2 will show the reader enough to enable him to complete the layout. Refer to the table of offsets, half-breadth of water line No. 2.
Point off these distances on the various stations from the center line, namely, on frame 1, 3 5/8"; frame 2, 8 4/8"; frame 3,1' 0 6/8"; frame 4, 1' 4"; frame 5, 1' 6 1/8"; frame 6, 1' 7 2/8"; frame 7, 1'
7 2/8"; frame 8, 1' 3/8"; frame 9, 1' 4 3/8"; frame
10, 0' 11 6/8"; frame 11, 0' 2 5/8". Drive small nails at these points, and bend a thin batten through them, passing it inside some and outside others as need be in order to properly fair up the lines, as explained in a previous paragraph.
BODY PLAN
To lay off the body plan, Figure 3, first produce the base line and then the center line. Lay off the water lines parallel to the base line and the station lines parallel to the center line. Scale off from these lines on the drawing the various frame lines and transfer these locations to the mould loft floor, taking all measurements from the corresponding line. Drive in small nails at these points and bend a thin batten, fairing up the line as may be required before striking in the line.
CHAPTER II
STEM AND STERN CONSTRUCTION
The stem is made up of four members, namely, Stem, Lower Stem, Apron, and Deadwood. The stern is made up of six members, Stern Post, Stern Post Knee, Shaft Log, Deadwood, Horn Timber and Transom.
Stem.—The stem (Figure 5) is the foremost boundary of the boat, being a continuation of the keel to the height of the vessel, at the fore extremity.
Lower Stem.—The lower stem is a curved piece placed in the angle formed by the apron and the upper end of the deadwood.
Apron.—The apron is the upper member of the stem on the inboard side of the boat. It is intended to strengthen the stem and afford wood for the reception of the outside planking and the heels of the foremost timber.
Deadwood.—The deadwood is the lower member of the stem on the inboard side of the boat. The deadwood becomes the foundation against which the heels of the forward frames are abutted.
Stern Post.—The stern post (Figure 6) forms the after boundary of the frame of the boat, being the after continuation of the keel to the height of
