Harbor Mine Planter
[Official US Navy photograph]
Flagship of the HDU
Fleet, USS YMP-2 (with YMP-1 alongside)
It had a length of 127 ft. and gross weight of 288 tons.
From this we planted/retrieved Mk. 51 Controlled mines.
YMP-2 was the only known navy ship without a rudder, propeller or an anchor!
ORIGINAL PROPOSED DESIGN SPECS
The vessel will be 127 Feet long with a 35-foot beam and 8-foot draft. It will be propelled by two 500-horsepower diesel engines through two Voith-Schneider cyclodal propellers, It is the first ship designed expressly for cyclodal propulsion to be built in this country. The propellers are captured German units. The cyclodal propeller differs radically from the conventional screw type propeller. The direction of thrust is controllable through 360 degrees. Hence, steering is accomplished through the propellers and no rudder is employed on the vessel. The system of propulsion is so flexible that the vessel may be brought out broadside from a dock in a crabbing motion. In tests conducted with a captured German vessel, equipped with cyclodal propellers, the vessel was brought to a standstill from full speed ahead in one-half the ship's length. This type of propeller should make the new mine planter highly maneuverable. Top speed is expected to be about 12 knots.
Coast Artillery Journal, January-February 1947
THE DAVID W. TAYLOR MODEL BASIN
WASHINGTON 7, D.C.
SGT. TRUMAN O. OLSON (YMP-2) EQUIPPED
WITH VOITH-SCHNEIDER CYCLOIDAL PROPELLERS
STANDARDIZATION TRIAL ANALYSIS
AND MODEL RESISTANCE TEST RESULTS
By George K. Brown
Prepared for The Board of Inspection and Survey
July 1953 - Report No. C-583
The standardization trials of the Sgt. Truman O. Olson (YMP-2), an experimental controlled mine planting prototype utilizing cycloidal propeller drive were authorized by the Chief of Naval Operations, (1)*, The Voith-Schneider cycloidal propellers installed on the YMP-2 were captured enemy equipment secured by the Transportation Corps Technical Team of the U.S. Army of Occupation at Heidenheim, Germany, during World War II and were shipped to the United States for evaluation. Figure 1 is a photograph of the YMP-2 taken in dry dock showing the propeller installation. The purpose of these trials was to evaluate the design and performance characteristics of this mine planter. Standardization trials on YMP-2 were conducted under the supervision of the Board of Inspection and Survey, in accordance with the trial agenda letter, over the measured mile course at Kent Island, Maryland, on 2125 May 31951 (2). Preliminary standardization curves and data were furnished the Board for distribution (3).
Type Voith-Schneider Cycloidal
Length on waterline (LWL)
Maximum Beam at (LWL)
Centerline skeg and propellers
Type Voith-Schneider Cycloidal BuShips Dwg. No. Index Nos.
3,156,125 - 3,156,261
Number of Propellers 2 Speed reduction of Shaft RPM
to Propeller RPM
3.28:1 Orbit Diameter 70.87 in. Length of Blades 39.37 in.
Max. blade chord width-bottom
Max. blade chord width-top
Max. blade thickness-bottom
Max. blade thickness-top
3.50 in. Manufacturer
SHIP TRIAL CONDITIONS
Trial Course: Kent Island, Maryland
Length of Trial Course: 6080 ft.
Depth of Water: 50 ft
Ship underbody paint: Formula 15 HP (Hot Plastic)
Date of Trial, 1951
Days out of Dock
4 - 7
Displacement in Tons
Mean Draft in ft. 9.78 9.30 Trim in inches, by stern 6 - Trim in inches, by bow - 2 Wetted Surface in sq. ft. 4797 4625 Specific Gravity of Sea Water 1.005 1.007 Temperature of Sea Water 65 ºF. 63 ºF. Wind (Beaufort Scale) 2-4 0-1
Note: Test results in Appendix 4, Table 5 show maximum speed over the measured mile and horsepower as 9.56 knots and 838 SHP with air injected into rotor wells and
9.16 knots and 930 SHP without air injection.
[Reference material courtesy of Ramon Jackson]
Derick S. Hartshorn -