4. The minimum radius of the curves is 5,577 feet (1,700 metres).[14] This curve, however, does not come in the Culebra Cut, where the bottom width is to be 200 feet, but north of Bas Obispo, where the bottom width is 500 feet. Most of the curves have a radius of 9,842 feet (3,000 metres). [14] _Vide_ p. 205 of General Abbot's "Problems of the Panama Canal" (1907). Slight changes in the projected course are made from time to time, so that this figure is subject to slight modification. In the Suez Canal,[15] outside Lake Timsah, there are five curves with a radius of 2,000 metres, or a little more, which are being enlarged to 2,500 metres (8,202 feet). The usual bottom width in these curves was 184 feet, but this is being increased to about 230 feet. The Kiel Canal has four curves with a radius of 1,000 metres (3,284 feet). [15] Report, Board of Consulting Engineers, p. 178. A reference to the accompanying plan (_vide_ Map, end of volume) of the Panama Canal will show that most of the curves are situate in Gatun lake, where the width of the canal proper is large, and where the spread of shallower waters secures better steerage. Thus the high-level Canal is not only deep and wide, but also much freer from troublesome curves than might be supposed from a casual inspection of its course. The details of the bottom width of the high-level Canal in its different parts are as follows:-- Feet. From the Atlantic entrance to Juan Grande (27 miles) 1,000 Juan Grande to Bas Obispo 500 Bas Obispo to a point about half-way between Empire and Culebra 300 Culebra Cut nearly to Pedro Miguel lock (about 4 miles) 200 Pedro Miguel to Pacific entrance 500 [Illustration: 100-TON WRECKING CRANE, GORGONA.] [Illustration: INTERIOR OF MACHINE SHOP, GORGONA.] Limon Bay being shallow, the deep water where a battleship can freely navigate or manoeuvre lies outside a line joining Colon Lighthouse with Toro Point, and at a distance of 7-1/2 miles from Gatun locks. From this distance the lock-excavation can now be plainly discerned from the deck of a ship without the aid of a glass. Here, when the Canal is complete, a ship will enter the buoyed channel of the submarine portion of the Canal, but this part of the channel does not lead directly towards the locks, which are not visible upon the face of the water. Moreover, they are presently hidden altogether by the land. Not until Mile 5, near Mindi, is reached does the course of the Canal, by a slight bend, open up the locks to uninterrupted view, and at this point the ship is already confined between banks. When the foot of the flight of three locks is reached a vessel will no longer proceed under her own steam, but be warped through.