YMP-2

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

 

Extracts from:

NAVY DEPARTMENT
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

 

INTRODUCTION

 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).

-3

 

TABLE 1
 SHIP CHARACTERISTICS

 

Type Voith-Schneider Cycloidal

Length on waterline (LWL)

127.5 ft.

Maximum Beam at (LWL)

35.0 ft.

Appendages

Centerline skeg and propellers

PROPELLER CHARACTERISTICS

Type Voith-Schneider Cycloidal
BuShips Dwg. No. Index Nos.
    3,156,000-  3,156,123
    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

9.00 in

Max. blade chord width-top

15.00 in.

Max. blade thickness-bottom

0.75 in

Max. blade thickness-top

3.50 in.
Manufacturer

J.M. Voith
 Machine Works,
Heidenheim, Germany

 

 

(4)

 

TABLE 2
 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)

 

 

Full Load

Light Load

Date of Trial, 1951

 21-24 May

25 May

Days out of Dock

4 - 7  

8

Displacement in Tons

595

545

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 F. 63 F.
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]

 


 
 
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