20:
155:
89:(width) and hence only a limited angle is possible for the guy-ropes to support very high masts. Thereby, the taller the ship's mast, the more narrow and unfeasible would be the angle between its support wires and its top. This is where a simple innovation like the crosstree helps to overcome such limitation.
96:
Each crosstree serves to spread another level of holding ropes on a fresh wider spar so as to provide support to the next mast top section. Effectively, the crosstree allows to extend the height, mount yet another layer of sail shrouds and option more wind power to the ships. The crosstree also
92:
The crosstree serves as a fresh base to spread the next level of supporting guy ropes, thereby providing a stable height extension to the masts. Without the crosstree, the ship's mast would have been severely limited in height, in relation to the beam of the ship.
74:
Any vertical structure like a mast is subject to dynamic swaying stress from wind, which levers immense force at the base of the mast. Such stress is countered through
78:
which are diagonally supporting ropes from mast top to its base. These ropes share the load on the mast tops and communicate that force to the base structure.
175:
134:
85:
so as to form an appropriate angular support against the sway the mast is exposed to, yet ships are fixed in their
159:
126:
119:
50:. They may also be mounted at the upper end of the topgallant to anchor the shrouds from the
8:
130:
43:
86:
59:
47:
31:
169:
39:
114:
51:
55:
82:
75:
19:
66:. In modern sailing vessels, spreaders serve the same purpose.
63:
35:
154:
81:
The taller the mast, the wider a base is required for the
118:
167:
54:(if fitted). Similar transverse spars remain on
18:
168:
113:
58:and motor vessel masts to secure wire
16:Structural element of sailing vessels
13:
97:serves to spread the shroud tops.
14:
187:
147:
153:
23:Line art drawing of crosstrees.
107:
69:
1:
125:. New York: Viking. p.
42:that are used to anchor the
7:
10:
192:
100:
34:at the upper ends of the
176:Sailing rigs and rigging
30:are the two horizontal
121:The Price of Admiralty
24:
22:
162:at Wikimedia Commons
25:
158:Media related to
183:
157:
141:
140:
124:
111:
191:
190:
186:
185:
184:
182:
181:
180:
166:
165:
150:
145:
144:
137:
112:
108:
103:
72:
62:or signal flag
48:topgallant mast
17:
12:
11:
5:
189:
179:
178:
164:
163:
149:
148:External links
146:
143:
142:
135:
105:
104:
102:
99:
71:
68:
15:
9:
6:
4:
3:
2:
188:
177:
174:
173:
171:
161:
156:
152:
151:
138:
136:0-670-81416-4
132:
128:
123:
122:
116:
110:
106:
98:
94:
90:
88:
84:
79:
77:
67:
65:
61:
57:
53:
49:
45:
41:
40:sailing ships
37:
33:
29:
21:
120:
115:Keegan, John
109:
95:
91:
80:
73:
27:
26:
70:Explanation
160:Crosstrees
52:royal mast
28:Crosstrees
83:guy-wires
76:guy ropes
56:steamship
46:from the
170:Category
117:(1989).
64:halyards
60:antennae
36:topmasts
101:Sources
44:shrouds
133:
32:spars
131:ISBN
87:beam
127:277
38:of
172::
129:.
139:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
.png)
