Woodyard D. (ed.) Pounders Marine diesel engines and Gas Turbines

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engine-mounted titanium plate heat exchanger is incorporated for durability and

minimal maintenance demands.

A number of options are offered to ease servicing and reduce downtime and

maintenance. The Centinel oil management system, for example, can extend the

time between, or even eliminate, oil changes, while the Eliminator ﬁlter replaces

disposable lube oil ﬁlters with a self-cleaning centrifuge. Working either together

or individually, says Cummins, these systems foster cost-effective maintenance

and reduce the potential for lube oil contamination during oil-related servicing.

Minimal changes to the footprint, mountings, ratings and optional equip-

ment of the KV engines were sought to ease installation of the QSK engines

for newbuilding and retroﬁt projects.

Quantum System electronics are driven by an ECM proven in rugged appli-

cations across previous Cummins platforms. The C-Command instrument pan-

els include a selection of modular monitoring and display options that assist

in protecting and enhancing engine operations. These facilities also help to

manage operating costs by logging critical parameters such as engine load,

duty cycle, speed and fuel consumption as well as providing diagnostic and

prognostic capabilities. A common point of connection in the customer inter-

face box simpliﬁes the link between engine electronics and ship systems, and

reduces installation complexity.

A comprehensive history of alarms and faults can also be logged for efﬁ-

cient trouble-shooting and service scheduling, the data downloadable via an

Ethernet connection. Direct access to the latest Cummins parts and service

information is accessible via the Internet from the panel itself. All C-Command

systems can help operators manage the engine life-cycle by pinpointing the

optimum speed for the best possible fuel efﬁciency under the given conditions,

says Cummins.

Earlier models in the Cummins programme include the KTA50-M2 model,

which became available from 1996. The 159 mm bore/159 mm stroke design

is produced in V16-cylinder form with ratings of 1250 kW and 1340 kW for

medium continuous duty and 1030 kW and 1180 kW for continuous duty appli-

cations. The running speeds range from 1600 rev/min to 1900 rev/min, depend-

ing on the duty; typical applications include ﬁshing vessels, tugs, crewboats

and small ferries.

The KTA50-M2 engine beneﬁted from a new Holset turbocharger, LT after-

cooling and gallery-cooled pistons. Cummins’s Centry electronics system con-

tributes to enhanced overall performance and fuel economy, providing adjustable

all-speed governing, intermediate speed controls, dual power curves, a built-in

hour meter and improved transient response. Diagnostic capabilities are also

incorporated.

Customer requests stimulated Cummins in 2007 to upgrade the KTA38-

MO engine to meet EPA Tier II emission levels as well as EU Stage IIIA regu-

lations. The resulting V12-cylinder/38-litres design was initially offered with

a rating of 634 kW at 1800 rev/min for continuous marine duty. Direct retroﬁts

for Tier I engine installations are facilitated.

Cummins 771

772 High-Speed Engines

DEutz

A long tradition in high-speed engine design was maintained by Deutz of

Germany (formerly Deutz MWM) whose last marine programme focused on

the 616 and 620 series with an upper output limit of 2336 kW for propulsion

and genset drives. Other high-speed engines produced under the Deutz banner

covered a power range down to 14 kW.

The 616 series is a 132 mm bore/160 mm stroke design covering propulsion

plant applications from 320 kW to 1360 kW at speeds up to 2300 rev/min by

V8-, 12- and 16-cylinder models (Figure 30.5).

The 170 mm bore/195 mm stroke 620 series design also embraces V8-, 12-

and 16-cylinder versions covering a power band from 829 kW to 2336 kW at

speeds up to 1860 rev/min for propulsion duty (Figure 30.6). Good exhaust gas

exchange and optimum combustion with minimal emissions are fostered by

cross-ﬂow cylinder heads and four valves per cylinder, while a relatively high

compression ratio promotes excellent cold-start characteristics and low fuel

consumption. High-pressure (HP) fuel injection further contributes to these

operating qualities. Correct swirl under both low load and full load conditions

is secured by the boost pressure-controlled throttle of the HALLO-Swirl sys-

tem, a variable swirl-supporting air intake system.

Outputs from 1035 kW to 3600 kW at 1000 rev/min are delivered by six,

eight and nine in-line and V12- and V16-cylinder versions of the 240 mm bore/

280 mm stroke 628 series, which can be operated on heavy fuels (RMK 35) as

well as marine diesel oil.

granDi motori triEStE

Grandi Motori Trieste (GMT) of Italy—which was absorbed into the Wärtsilä

Corporation—focused its high-speed engine developments on a 230 mm bore

design offered in several versions for commercial and naval propulsion appli-

cations as well as for genset drive duties (Figure 30.7). A heavy fuel-burning

model was available for unifuel machinery installations while a non-magnetic

version could be speciﬁed for minehunters.

The series was produced in standard (B230) form with a stroke of 270 mm

and in BL230 long stroke (310 mm) form, later versions beneﬁting from

improved cooling and turbocharging arrangements for higher outputs at speeds

up to 1200 rev/min. The B230 had a rating of 210 kW/cylinder and the BL230 a

rating of 225.5 kW/cylinder. Both types were produced in in-line four to V20-

cylinder conﬁgurations. A two-stage turbocharged version with variable com-

pression ratio, the BL 230 DVM, developed 283 kW/cylinder at 1050 rev/min

on a mean effective pressure of 25.1 bar to provide a compact plant for cor-

vettes and frigates. The V20-cylinder model delivered 5660 kW.

A BL230P version was developed for operation on heavy fuel up to IFO

500 with a maximum speed of 1000 rev/min and a power rating—190 kW/cyl-

inder—lower than the gas oil-fuelled models. Its special features included:

composite pistons with forged steel crowns and plasma-coated rings in the ﬁrst

grandi motori trieste 773

FigurE 30.5 v12-cylinder block of Deutz 616 series engine

FigurE 30.6 v16-cylinder version of Deutz 620 series engine

774 High-Speed Engines

FigurE 30.7 gmt Bl230 engines in a genset installation

groove for wear resistance; Nimonic A material exhaust valves; valve rotators;

cooled fuel injection valves; and oversized fuel injection pumps for enhanced

atomization and combustion. Other variants in the engine programme targeted

natural gas and LPG burning installations.

A highly rigid cast iron main structure for the 230 mm bore engine incorpo-

rates the water, oil and air manifolds, virtually eliminating external pipes and

fostering compactness. Camshafts, oil cooler, oil, water and fuel pumps, and

ﬁlters are arranged for accessibility; and pistons and connecting rods are with-

drawable from the top.

GMT

’s high-speed portfolio also included the A210 series, the 210 mm

bore/230 mm stroke design developing 170 kW/cylinder at 1500 rev/min on a

mean effective pressure of 16.2 bar. A programme embracing V6- to V20-cylinder

models covered output demands up to 3400 kW. A special version designed

for submarine propulsion—the compact and lightweight A210SM—beneﬁted

from anti-noise, shock and vibration characteristics. An ability to operate in

severely inclined positions was also addressed, along with ease of access for

maintenance.

iSotta FraSCHini

A family of high-speed engines from Isotta Fraschini, part of Italy’s Fincantieri

group, is headed by the 170 mm bore/170 mm stroke 1700 series which is

available in different versions for light, medium and heavy propulsion duties in

commercial and military vessels, as well as for genset drives. A non-magnetic

variant was developed for mine warfare vessels.

The 1700 series embraces V8-, 12- and 16-cylinder models, all with a 90°

conﬁguration arranged on a high-tensile alloy iron crankcase and featuring a

direct fuel injection system and four valves per cylinder. Upgrades raised the

power output, the largest model—the V1716 T2—then offering up to 2595 kW

at 2100 rev/min, compared with its previous maximum rating of 2350 kW at

the same speed.

man (HolEBY)

In 1995 MAN Diesel’s genset engine specialist Holeby Diesel of Denmark

supplemented its popular L23/30H and L28/32H medium-speed auxiliary

prime movers with the innovative higher speed L16/24 series. The 160 mm

bore/240 mm stroke design (Figure 30.8) was conceived as a new generation

1000/1200 rev/min engine dedicated to genset drives and capable of operating

on an unrestricted load proﬁle on heavy fuel up to 700 cSt/50°C viscosity. The

current programme embraces ﬁve-, six-, seven-, eight- and nine-cylinder mod-

els covering a power range from 450 kW to 990 kW, following a 10 per cent

uprating to 110 kW/cylinder introduced in 2004.

The main problem in burning heavy fuel oil in small high-speed engines is

ignition delay. Smaller quantities of the volatile, easily combustible hydrocar-

bon fractions are present in such fuels than in lighter diesel fuels. The L16/24

man (Holeby) 775

776 High-Speed Engines

FigurE 30.8 Cross-section of man l16/24 genset engine. note the separate cam-

shafts for the gas exchange valves (left) and fuel injection (right)

designers addressed the problem by adopting a number of measures to achieve

excellent heavy fuel combustion even at part- and low load operation: a higher

injection pressure (1500 bar), a higher opening pressure for the fuel valve,

smaller nozzle hole diameters in the valve and a higher compression ratio

(15.5:1). The maximum combustion pressure is 180 bar. Another contribution

came from a cylinder head design reﬁned to improve the swirl of fuel in the

combustion chamber.

Support-function components were traditionally distributed around the

engine block and connected with externally mounted supply pipes. The prac-

tice was reversed for the L16/24 engine: all support elements—oil and water

pumps, coolers, ﬁlters, and safety and regulator valves—are arranged in a sin-

gle front-end box for ease of accessibility and maintenance (Figure 30.9); and

the supply channels are cast into the block for maintenance-free operation.

Virtually all the engine’s internal supply lines are channelled through the cool-

ing water jacket and cylinder head. The arrangement considerably simpliﬁes

the overall design, reducing the overall number of components by some 40 per

cent compared with earlier engines. The front-end box system components can

be exchanged using clip-on/clip-off couplings without removing any pipes.

High rigidity was sought from a monobloc cast iron engine frame whose

elements are all held under compressive stress. The frame is designed to accept

an ideal ﬂow of forces from the cylinder head down to the crankshaft and to

yield low surface vibrations from the outer shell. Two camshafts are located in

man (Holeby) 777

FigurE 30.9 man l16/24 engine. all main support ancillaries are grouped in a

single front-end box for ease of access

778 High-Speed Engines

the frame: the camshaft for the inlet/exhaust valves is arranged on the exhaust

side in a very high position; and the fuel injection camshaft is on the service

side of the engine.

Covers in the frame sides offer access to the camshafts and crankcase;

some of the covers are arranged to act as relief valves. There is no cooling

water in the frame. The frame box is designed to minimize noise emission, the

inner frame absorbing all the engine forces and the outer frame forming a stiff

shell with minimal vibration (Figure 30.10). The main bearings for the under-

slung crankshaft are carried in heavy supports by tie-rods from the intermedi-

ate frame ﬂoor and secured by bearing caps. The caps are provided with side

guides and held in place by studs with hydraulically tightened nuts. The main

bearing features replaceable shells which are ﬁtted without scraping.

Both engine and alternator are mounted on a rigid base frame that acts as

a lubricating oil reservoir. Specially designed engine mounts reduce noise and

vibration.

The centrifugal cast iron cylinder liner, housed in the bore of the engine

frame, is clamped by the cylinder head and rests on its ﬂange on the water

jacket; it can thus expand freely downwards when heated during engine opera-

tion. The liner is of the high ﬂange type, the height of the ﬂange matching the

water-cooled area to give a uniform temperature pattern over the entire liner

surface. The liner’s lower part is uncooled to secure a sufﬁcient margin for

cold corrosion at the bottom end. There is no water in the crankcase area. Gas

sealing between liner and cylinder head is effected by an iron ring. The liner is

ﬁtted with a slip-ﬁt-type ﬁre ring at its top to reduce lubricating oil consump-

tion and bore polishing.

running gear

The cast iron cylinder head, with integrated charge-air receiver, is made in

one piece and incorporates a bore-cooled thick-walled bottom. It has a central

FigurE 30.10 noise emission and vibration from the man l16/24 engine are

minimized by the inner frame, outer shell and cover arrangement

bore for the fuel injection valve and a four-valve cross-ﬂow conﬁguration with

a high ﬂow coefﬁcient. The valve pattern is turned about 20° to the axis to

achieve an intake swirl promoting optimized combustion. The head is hydrau-

lically tightened by four nuts acting on studs screwed into the engine frame.

A screwed-on top cover for the head has two main functions: oil sealing the

rocker chamber and covering the complete top face of the head.

Air inlet and exhaust valve spindles are of heat-resistant material and their

seats armoured with welded-on hard metal. All the spindles are ﬁtted with

valve rotators to ensure an even temperature on the valve discs and to prevent

deposits forming on the seatings. The cylinder head is provided with replace-

able valve seat rings of heat-resistant steel, and the exhaust valve seat rings are

water cooled. The seating surfaces are hardened to minimize wear and prevent

dent marks.

The valve rocker arms are actuated through rollers, roller guides and push-

rods. The roller guides for the inlet and exhaust valves are mounted in the

water jacket part. Access for dismantling is provided by a side cover on the

pushrod chamber. Each rocker arm activates two spindles via a spring-loaded

valve bridge with thrust screws and adjusting screws for valve clearance. The

valve actuating gear is pressure feed-lubricated from the centralized lubricat-

ing system, through the water chamber part and from there into the rocker arm

shaft to the rocker bearing.

The oil-cooled pistons comprise a nodular cast iron body and forged steel

crown with two compression rings and one scraper ring ﬁtted in hardened

grooves. The different barrel-shaped proﬁles of the compression rings and their

chromium-plated running surfaces aim to maximize sealing and minimize wear.

The piston has a cooling space close to the crown and the ring zone which is

supplied with oil from the engine lubricating system. Heat transfer, and thus

cooling, is promoted by the shaker effect stimulated by the piston movement.

Oil is supplied to the cooling space through channels from the oil grooves

in the piston pin bosses. Oil is drained from the space through ducts located

diametrically to the inlet channels. The piston pin is fully ﬂoating and kept in

position in the axial direction by two circlips.

The die-forged connecting rod has a big end with a horizontal split and

bored channels to transfer oil from the big end to the small end. The big end

bearing is of the tri-metal type coated with a running layer. The bearing shells

are of the precision type and can therefore be ﬁtted without scraping or any

other adaptation. The tri-metal small end bearing is pressed into the connecting

rod. The bush is provided with an inner circumferential groove and a pocket

for distributing oil in the bush itself and for supplying oil to the pin bosses.

A one-piece forged crankshaft with hardened bearing surfaces is suspended

in underslung, tri-metal main bearings coated with a running layer. To attain a

suitable bearing pressure and vibration level the crankshaft is equipped with

counterweights which are attached to the shaft by two hydraulic screws. At its

ﬂywheel end, the crankshaft is ﬁtted with a gearwheel which, through two inter-

mediate wheels, drives the twin camshafts. Also mounted here is a coupling

man (Holeby) 779

780 High-Speed Engines

ﬂange for the alternator. At the opposite (front) end is a gearwheel connection

for the lubricating oil and water pumps.

Lubricating oil for the main bearings is supplied through holes drilled in

the engine frame. From the main bearings the oil passes through bores in the

crankshaft to the big end bearings and thence through channels in the connect-

ing rods to lubricate the piston pins and cool the pistons.

Separate camshafts for the inlet/exhaust valves and the fuel pump facilitate

adjustment of the gas exchange settings without disturbing the fuel injection

timing (Figure 30.8). Likewise, it is possible to adjust fuel injection without

disturbing gas exchange parameters. The resulting ﬂexibility allows engine

operation to be adjusted and optimized for fuel economy or low NOx emis-

sions. The camshafts are mounted in bearing bushes ﬁtted in bores in the

engine frame. The valve camshaft is arranged in a very high position on the

engine exhaust side to secure a short and stiff valve train and reduce mov-

ing masses. The fuel injection camshaft is arranged on the service side of

the engine.

Both camshafts are structured in single-cylinder sections and bearing sec-

tions in such a way that disassembly of individual cylinder sections is possible

through the side openings in the crankcase. The camshafts and governor are

driven by the main gear train at the ﬂywheel end of the engine, rotating at a

speed half that of the crankshaft. The lubricating oil pipes for the gearwheels

are equipped with nozzles adjusted to apply lubricant at the points where the

gearwheels mesh.

All fuel injection equipment is enclosed securely behind removable cov-

ers. Each cylinder is individually served by a fuel injection pump, HP pipe and

injection valve with uncooled nozzle. The injection pump unit, mounted on the

engine frame, comprises a pump housing embracing a roller guide, a central

barrel and a plunger. The pump is activated by the fuel cam, and the volume

injected is controlled by turning the plunger. The fuel injection valve is located

in a valve sleeve in the centre of the cylinder head, its opening controlled by

the fuel oil pressure and closure effected by a spring.

The HP fuel pipe is led through a bore in the cylinder head surrounded by a

shielding tube. The tube also acts as a drain channel to ensure that any leakage

from the fuel valve and the HP pipe is drained off.

A lambda controller ensures that all injected fuel is burnt, countering the

internal engine pollution and increased wear that might otherwise result from

genset step loading.

A constant pressure turbocharging system embraces an MAN Diesel NR/S

turbocharger purpose-designed for the L16/24 engine, charge-air cooler, charge-

air receiver and exhaust gas receiver. The charge-air cooler is a compact two-

stage tube unit deploying a large cooling surface.

A patented ‘intelligent’ cooling water system was designed to secure an

optimized temperature across the engine operating band from idling to full

load. The system, which accepts freshwater within the 10–40°C temperature

range, has one inlet and one outlet connection. Its two pumps, in combination