Progress ZT 300

Kombinat progress agricultural machinery
Progress ZT 300
ZT 300
Manufacturer:	Tractor factory Schönebeck
Sales designation:	ZT 300
Production period:	1967-1984
Engines:	6.56 liters, 66-74 kW
Traction:	on wet ground: ZT 300: 13 kN ZT 303: 18 kN on slopes: ZT 303: 34 kN
Length:	4690 mm
Width:	2020 mm
Height:	2620 mm
Wheelbase:	2800 mm
Gauge:	front: 1550 mm rear: 2000 mm
Standard tires:	front: 7.50-20 10PR rear: 18.4 / 15-30 8PR
Top speed:	28.84 km / h
Empty weight:	4820 kg
Previous model:	RS14
Successor:	Progress ZT 320

The ZT 300 pulling tractor is a traction class 20 kN tractor, which was manufactured from 1967 to 1984 in the combine progress agricultural machinery - VEB Tractorswerk Schönebeck (Elbe). It replaced the tractors of the Famulus series. The ZT 300 denotes both the base vehicle and the entire series based on it. From September 1967 to the beginning of 1984 a total of 72,382 tractors of the ZT series were built. A ZT 303 cost 81,000 marks in the early 1980s  . The ZT-300 series was replaced by the ZT-320 series .

chronology

The "ZT", as it was usually only called colloquially, was available in several versions:

• ZT 300 : The basic vehicle
• ZT 303 : Like the base vehicle, with additional front axle drive (built from 1972, most popular model)
• ZT 304 : Road tractor, without underload shift stage, PTO shaft and work lights, but with simple hydraulic connections
• ZT 305 : Based on ZT 303, with dual-circuit brake system and braked front axle, standard twin tires
• ZT 300 GB : Based on the ZT 300, with caterpillar drive instead of wheels (only small series)
• ZT 403 : Based on ZT 303, with a more powerful 6 VD 14.5 / 12-1 SRW engine with 110 kW (conversion from ZT 303)
• ZT 307 : Based on ZT 305, with a more powerful 6 VD 14.5 / 12-1 SRW engine with 110 kW (prototype only)

• 

  ZT 300-C

• 

  ZT 303

• 

  ZT 304

• 

  ZT 305-A

Some tractors have become two-way converted -Traktoren and as Rangiergeräte especially in GDR small businesses with railway connection used. They were equipped with the necessary signaling devices ( peak signal , tail signal ) and hydraulically lowerable flange wheels.

technology

Training at the ZT 300

Emblem of the Tractor Works (TW) Schönebeck attached to the radiator grille

A ZT 303 tractor on a postage stamp of the German Post of the GDR

Rear view

ZT 303 with twin tires

Diesel engine of a ZT 303

The ZT 300 is a semi-frame construction tractor. The axles are rigid, the front axle is designed as a swing axle, the rear axle unsprung. The ZT 300 has control and power hydraulics . The engine is an in-line four-cylinder diesel engine of the type 4 VD 14.5 / 12-1 SRW with direct injection as in the IFA W50 . It had a displacement of 6.56 liters and initially developed 66 kW at 1,500 rpm, the output was increased in 1973 to 68 kW and in 1978 again to 74 kW at 1,800 rpm. The maximum torque is 422 Nm at 1350 rpm, the minimum specific fuel consumption of 238 g / kWh is 1,350 rpm. A three-point linkage and a PTO are available for attachments . From 1974 onwards, a traction boosting device (control hydraulics) could be installed as an option, which pushes up the attachment so that its weight acts more strongly on the rear axle to increase traction. The tractors of the ZT-300 series have a partial powershift transmission with three gears that can be shifted into three groups. A total of six reverse and nine forward gears are available, which enables a speed range from 3.1 to around 30 km / h. The power of the motor is transferred to the gearbox via the pneumatically assisted DK 80 double clutch . The second stage of the clutch engages or disengages the PTO shaft (s) and the so-called underload shift stage. Switching on the underload stage and thus increasing the torque takes place without having to interrupt the flow of power to the drive wheels. The rear axle has a differential lock . The steering of the first models is a mechanical rack and pinion steering, which is hydraulically assisted; later models got a fully hydraulic steering. All tractors in the ZT-300 series have internal shoe brakes on the rear wheels. The brake can also act as a steering brake. The hand-operated parking brake is a band brake that acts on the brake drums of the rear axle. The tractor may tow a maximum of 24 tonnes of trailer load, then the trailer must be equipped with a compressed air brake system.

Special features of the all-wheel drive types

The all-wheel drive switches on automatically via a roller freewheel when the slip on the rear axle exceeds a target value of eight percent and switches off when it falls below seven percent. The front axle was also installed on the IFA W50-LA truck and was modified accordingly for the tractor. Like the rear axle, it can be locked with a limited slip differential. The type ZT 305 also had a compressed air-assisted dual-circuit brake system, with a braked front axle, larger tires at the front and rear and widened wheel arches and twin tires at the rear. It was specially developed for use on slopes with an incline of up to 45%.

Technical specifications

Valid for all vehicles built after 1978

	ZT 300	ZT 304	ZT 300 GB	ZT 303	ZT 305	ZT 403	ZT 307
engine
Engine designation	4 VD 14.5 / 12-1 SRW					6 VD 14.5 / 12-1 SRW
Engine type	Four-cylinder in-line four-stroke diesel engine with direct injection					Six-cylinder in-line four-stroke diesel engine with direct injection
Cooling system	Water cooling with pump circulation
Bore × stroke	120 × 145 mm
Displacement	6560 cc					9839 cc
rated capacity	74 kW at 1800 min -1					110 kW at 2000 min -1
Torque	Maximum torque 422 Nm at 1350 min -1					Rated torque 525 Nm at 2000 min -1
Fuel consumption	238 g / kWh					?
Power transmission
Power transmission on	Rear axle			Rear axle, from 6% slip additionally on the front axle
Standard tires	front: 7.50-20 10 PR back: 18.4 / 15-30 8 PR		Caterpillars	front: 12.5-20 A19 rear: 18.4 / 15-30 AS 8 PR	front: 16-20 AS rear: 18.4-34 AS 10 PR	front: 16-20 AS rear: 23.1 / 18-26
coupling	Double clutch DK 80 with underload switching stage
transmission	Partly powershift transmission with three gears and three groups, groups I and II reversible
PTO	Clutch-operated PTO at 540 min -1 or 1000 min -1 , optional front or intermediate PTO	no	Clutch-operated PTO at 540 min -1 or 1000 min -1 , optional front or intermediate PTO	Clutch-operated PTO at 540 min -1 or 1000 min -1
Hydraulics	Three-point power lift with automatic control, 147 bar working pressure, lifting force 17.65 kN, swivel angle 80 °	only for steering	Three-point power lift with automatic control, 147 bar working pressure, lifting force 17.65 kN, swivel angle 80 °
other systems
Braking system	rear inner shoe brake, hydraulically operated, can be used as a steering brake		Cletrac brake	rear inner shoe brake, hydraulically operated, can be used as a steering brake	Dual circuit brake system, rear inner shoe brake, hydraulically operated, front drum brake, Compressed air support	rear inner shoe brake, hydraulically operated, can be used as a steering brake	Dual circuit brake system, hydraulically operated, rear inner shoe brake, front drum brake, Compressed air support
Electrical system	2 × lead acid accumulator 12 V, connected in parallel , push screw drive starter , 24 V, 2942 W alternator 12 V, 500 W.
mass and weight
length	4690 mm				4690 mm	4890 mm	4890 mm
width	2020 mm				3263 mm	2020 mm	3263 mm
height	over hood: 1800 mm
Gauge	1550/2000 mm		2000 mm	1550/2000 mm	1850/2800 mm	1550/2000 mm	1850/2800 mm
wheelbase	2800 mm		no wheelbase	2800 mm
Ground clearance	460 mm			319 mm
Weight	4820 kg			5255 kg	6520 kg
Maximum permissible trailer load	24 t

Forward and reverse speeds

Speeds in km / h
Group - gang	forward	backward
Group I - 1st gear	3.02	3.12
Group I - 2nd gear	4.70	4.86
Group I - 3rd gear	6.45	6.71
Group II - 1st gear	3.76	3.88
Group II - 2nd gear	5.86	6.06
Group II - 3rd gear	9.27	9.59
Group III - 1st gear	11.67	-
Group III - 2nd course	18.19	-
Group III - 3rd gear	28.84	-

Painting

The tractors of the progress ZT 300 series were available in four possible color combinations:

• Blood orange / gray white / squirrel gray
• Sky blue / gray white / squirrel gray
• Siena green / gray white / squirrel gray
• TGL 21196 chlorobuna green

• 

  ZT 300 in sky blue

• 

  ZT 300 in blood orange

• 

  ZT 300 of the NVA in chlorobuna green

literature

• Achim Bischof: Tractors in the GDR. Podszun, Brilon 2004, ISBN 3-86133-348-1 .
• Klaus Tietgens : Progress ZT 300. Type history and technology. GeraMond, Munich 2014, ISBN 978-3-86245-575-1 .
• Jan Welkerling: PROGRESS in all ears. GDR agricultural machinery in use. 2005, (illustrated book).

Web links

ZT 300

Commons : Progress ZT 300  - Collection of pictures, videos and audio files

Wikibooks: Tractor Lexicon: Progress Universal Tractor ZT 300  - Learning and Teaching Materials

• GDR agricultural machinery ZT 300
• Bahn-Galerie.de two-way ZT 300

ZT 303

Commons : Progress ZT 303  - Collection of pictures, videos and audio files

Wikibooks: Tractor Lexicon: Progress Universal Tractor ZT 303  - Learning and teaching materials

Individual evidence

1. ↑ ^{a b c} Chief Engineer R. Blumenthal: Innovations on the pulling tractors ZT 300 and ZT 303 for tillage . Published in agrartechnik , Volume 28, Issue 10, October 1978
2. ↑ ^{a b c d} VEB IFA Motorenwerke Nordhausen: Diesel engine 4 VD 14.5 / 12-1 SRW repair manual (PDF) page 7. 2nd edition. VEB Fachbuchverlag Leipzig, 1986.