XK1 prototypes (PV-1 and PV-2) tests

 

TO: GEN KEITH, CDR DARCOM, ALEXANDRIA VA

SUBJ: XK1 ENGINE FAILURES

Q. BACKGROUND:

A. The republic of korea indigenous tank (rokit) program is currently in phase ii which was scheduled to end in june 1984. the end date is now projected for September 1984.

B. During phase II. Two full scale ROKIT prototypes have been designed, fabricated, and are undergoing testing at aberdeen proving ground (APG).

C. Two prototypes, designated as PV-1 and PV-2, were completed in august 1983 and November 1983. Testing began at APG during November 1983 and January 1984 to verify that the components, subsystems, and prototype vehicles meet the development specification.

D. PV-1 and PV-2 are powered by 1200 hp diesel engine, Teledyne continental motors (TCM) model AVCR 1790, driving an automatic trans­mission, Zahnradfabrik Friedrichshafen (ZF) model LSG 3000, which has differential steering and braking functions. The AVCR 1790 is a variable compression ration (VCR) engine.

E. PV-1 is a nonballistic automotive test rig (ATR) with a non operational turret. PV-1 Is planned to be used for all of the automot­ive performance subtests and the endurance and reliability testing.

F. PV-2 is a fire control test rig (FCTR) and is fully operational version of XK1 tank. it is planned to be used for all of the fire control subtests.

G. The phase II program is being conducted under the provisions of a commercial firm-fixed-price contract between the rok ministry of national defense (MND) and general dynamics land systems division (GDLS). tee us government's role is one of providing advice and assist­ance to the ROK program manager, and as such, has no control over the execution of the contract.

 

AUTOMOTIVE TEST RESULTS:

A. during automotive performance test from December 1983 to 5 April 1984, pv-1 failed to meet the following required performances:

 

	REQUIRED	MEASURED
acceleration verification test	10.5 Second	14.6 Second
	0 to 19.8 MPH	0 to 19.8 MPH
60 percent grade slope test	9.7 MPH	NOT ABLE
10 percent grade slope test	15.2 MPH	18.6 MPH
Fuel consumption test	1.0 miles/gallon	.6 miles/gallon

 

B. A decision on retest of the corrective actions will be made prior to 1 may 1984.

 

2. ENGINE FAILURE HISTORY:

A. PV-1 experienced loss of power on 13 March 1984. subsequent investigation revealed damage to several of the VCR pistons and valves the engine was replaced with the spare and shipped to TCM for failure analysis and repair.

B. The new engine experienced repeated low oil pressure warning indications subsequent investigation indicated excessive oil pressure fluctuation. A decision was made on 27 March 1984 to suspend pv-1 testing pending repair of the engine.

C. ON 5 APRIL 1984, THE PV-2 engine failed while enroute to the firing range. The investigation revealed damage to one of the VCR pistons and valves. A decision was made at that time to ship both engines to TCM for rebuild.

 

D. THE ENGINE FAILURE	HISTORY IS AS	SHOWN BELOW:
	test vehicle	operation
	milage	hour	failure
	net/total	net/total	date
FIRST ENGINE FAILURE PV-1	949/949	75/75	13mar84
SECOND	419/1368	20/95	27mar84
THIRD "	101/101	59/59	5apr84

 

4. REPAIR OF FAILED ENGINES:

A. TCM plans to rebuild all three engines using fixed pistons instead of the VCR pistons. The TCM position is that this will not degrade the horsepower. An evaluation of teat position is underway.

B. The rebuild time schedule for the first engine is 24 April 1984 second engine, 1 May 1984. Third engine time schedule has not been determined.

 

5. TEST SCHEDULE:

During the mid-point review meeting, (3-13 April 1984), the ROK PM representatives requested that the first available engine be installed in PV-2.

PV-2 will then resume fire control testing, and the second engine will be installed in PV-1. at present, the endurance test has completed about one third of the total mileage which is 2400 km (1500 miles). A revised testing plan will be coordinated before 1 May 1984.

 

6. SHIPPING SCHEDULE OF PV-1 TO KOREA:

PV-1 is scheduled to be shipped to Korea on 1 august 1984 for public demonstration on 1 October 1984 (Korean National Army Day). This requirement has priority over the completion of automotive testing. Engines will be available to support this requirement. In case the planned automotive test of PV-1 cannot be accomplished prior to the shipping date, PV-2 will be used to complete the required portions of the automotive test.

1. TESTING:

A. PV-1 endurance testing began 14 Jun 84. On 16 Jun 84,

A major fire occurred in the engine compartment. Damage to engine, left fuel cell, hydraulic lines, electrical lines and left brake occurred. Possible damage to left final drive and transmission. All testing on PV-1 Has been suspended and the tank has been released to GDLS for return to the pioneer engineering building, Warren, MI. It is expected repairs will take until 1 Aug 64. a suspected cause of fire is a short in the main power cable assembly. Investi­gation is on-going.

B. PV-2 continuing live fire control checks at APG. The tank successfully finished ballistics solutions on 20 Jun 84 and has now fired 56 rounds of a 900 round main gun firing program. No major problems. The power pack was removed on 21 Jun 84 for check to assure similar shorting conditions did not exist as in PV-1.

2. PROGRAM ISSUES:

A. Follow-on MOU hand carried to DA on 15 Jun 84. Staffing in process .

B. Gun forgings for ROK - DSAA has finalized case.

Case at ROK embassy for approval.

C. ESP PART I - Expect ROK to fund 29 Jun 84. In-country start of work (SOW) meting scheduled for 9-13 July with facilities tour following from 17 - 20 July. PM, tank systems will have rep­resentatives attending.