Q: 1.2.1 What do the Demag codes mean?

A: The Demag codes can be explained in the following way:

Type of crane

The first two letters denote the type of the crane:

AC

All Terrain Crane. This code ist used for mobile cranes with a telescopic boom. (Even if the ”all terrain” capability isn’t really given – at least at very large cranes.)

CC

Crawler Crane. (All Terex-Demag crawler cranes have a lattice boom.)

PC

Pedestal Crane.

TC

Truck Crane. This rather unspecific code is used for mobile cranes with a lattice boom.

Crane class

The number (mostly four digits) after the crane-type designator denoted the maximum load moment of the crane, measured in metre-tons (metric). This figure was sometimes given in a rounded off, approximate way.
But since 1998, Terex-Demag use a different scheme on telescopic cranes: Like other manufacturers, the stroke load measured in metric tons is used.
Unfortunately in case of newer cranes, the numbers are still four-digit ones but keep getting more and more non-descriptive. Since it is not possible to define general rules whether the number describes real data or not, a look on the lifting capacities tables of the individual crane is the only way out.
Sometimes, there is another digit after this code, separated by a hyphen. This denotes the generation of this crane with the very first version being counted as zero generation and omitted.

Example

According to the explanations above, you can have a look at the following example:

AC 500-2

A mobile crane with telescopic boom (because of “AC”) with 500 metric tons (551 sht) of stroke load (because of the three-digit number “700”) in a twice reworked version (because of “-2”).

Boom configurations

The following letter code is used to denote the various boom configurations of lattice boom cranes:

S

Schwer (“heavy”; only when followed bei a H, W or F; refers to the cross-section of the boom parts.)

L

Light. (Only when followed bei a H, W or F; refers to the cross-section of the boom parts.)

SL

Superlift – this always means a derrick mast with suspended ballast.

SSL

Sideways Superlift – only used on telescopic booms.

H

Hauptausleger – main boom.

W

Wippspitze – luffing fly jib.

F

Fixed fly jib.

Q: 1.2.3 What do the Liebherr codes mean?

A: The Demag codes can be explained in the following way:

Type of crane

The first two letters describe the type of crane:

L

Liebherr

T

telescopic boom

G

Gittermast-(Kran) – lattice boom (crane)

M

mobile crane

R

(Gittermast-)Raupenkran – crawler crane (with lattice boom).

C

City Class crane

MK

Mobilbaukran – folding crane mounted on a truck undercarriage.

D

Derrick mast (only used in inofficial designations – with the exception of the Spacelifters)

Crane class

The four-digit number describes the maximum lifting capacity of the crane measuered in metric tons and increased by 1.000. There is one exception from this rule: When dealing with cranes of the MK series, die number denotes the rounded maximum load moment of the crane measured in metre-tons.

Additional to this, there might be another single digit. If this number is separated by a hypen (“-”) from the rest of the code, it describes the number of axles on the undercarriage. (This figure is only written, when the undercarriage is available in different versions with different numbers of axles.) If the digit is separated by a slash (“/”), it denotes the generation of the crane with the very first version beeing the zero generation which number ist omitted.

In 2004, both schemes were combined and simplified. Now a hyphen ist at first followed by a digit denoting the number of axles, a period and another digit describing the generation. Now the generations are counted from 1 onwards and with the change of the naming-scheme, all affected cranes received a generation number of “1”.

Examples

According to the explanations above, you can have a look at the following examples:

LTM 1035-3

A Liebherr telescopic mobile crane (because of “LTM”) with 35 metric tons (38.5 sht) of stroke load (because of “1035”) and three axle undercarriage (because of “-3” – this crane was also available in a two axle configuration).

LTM 1500-8.1

A Liebherr telescopic mobile crane (because of “LTM”) with 500 metric tons (551 sht) of stroke load (because of “1500”) and eight axle undercarriage (because of “-8”) in the first generation (because of “.1”).

LR 1750

A Liebherr crawler crane with lattice boom (because of “LR”) with 750 metric tons (826 sht) of stroke load (because of “1750”).

Boom configurations

The following letter code is used to denote the various boom configurations of lattice boom cranes:

S

Schwerer Hauptmast – heavy main boom (refers to the cross-section of the boom parts).

SL

Main boom with heavy (schwer) and light elements (refers to the cross-section of the boom parts).

W

Wippspitze – luffing fly jib.

D

Derrick mast.

B

Suspended ballast

BW

Ballastwagen – Ballast trailer

V

Heavy, fixed fly jib

K

Knickausleger – articulated boom

Q: 1.5.1 How many AK850s were built?

A: Only two were built.

The AK 850-103 was delivered to Schmidbauer in 1982 where it was in use for 25 years.
Since for transportation, the crane exceeded the permittable axle loads for German roads the lifting winches/hoists and spools had to be removed every time the crane was moved to a new job. This was very time consuming and also wasted money and other resources. When the crane was being overhauled by AKS in 1998 the main superstructure was separated into 2 pieces, 1 part being the main hoists (transported on the cranes main carrier) and the other part the auxiliary hoists and A frame (transported separately) thus eliminating the need to remove the spools for transport and also speeding up rigging and derigging.
Also when the crane was new it only had a main boom and a luffing jib. When Schmidbauer had the AK 680 they took the parts from this crane for the Maxilift (backmast) system, and used them on their AK 850. In 2007, the crane was sold to Wheelers in Australia.

The second AK850 was built with a separated superstructure originally and was given therefore the designation “AK 850-104”. (Contrary to the later used “GT” designation.) Due to the additional space needed for the connection, the superstructre of this crane is as long as on the AK 912s, thus being able to lift 1,200 metric tons (1,322 sht) with Maxilift equipment. It was originally supplied to Toense in 1984, then in 1988 it was bought by Franz Bracht.Then it was bought by Interlift UK (and modified to full AK 912 GT specification) and combined with Al Jaber’s fleet, then after the collaspe of Interlift it went to Baldwins, after the bankruptcy of Baldwins the crane now works with ALE.
For transportation of the removable section of the superstructure a special vehicle was built by Gottwald, the AK 850-63 TR, remarkably equipped with a driving cab from a MAN truck. It has a special platform on the back so that the superstructure can be raised and fixed into position, regardless of whether the ground is level or not.
This crane also had a fixed heavy load jib of 8–10 m (25–35 ft) length, but Al Jaber kept this part when they had the crane and still have it to this day.

Q: 1.5.3 How many AK 912s were built?

A: Three were built.
The AK912 looks outwardly similar to the AK 850, but the main revolving superstructure and A frame is around 55 cm (22″) longer, which results in a longer lever arm for the ballast weights and therefore enables lifting heavier loads.

The first AK 912 was built in 1985 and was given the designation AK 912-103. It was built for Al Jaber in the United Arab Emirates, and is still there today. It is different to the other two examples in that instead of six axles ahead of the slew ring and four behind (6+4 formation) it has seven axles ahead and three behind. (7+3) This is also because it does not have a separated superstructure, unlike the other two.

The second crane was built in 1986 and designated AK 912-103 GT. It has a divisible superstructure, transported on a special vehicle built by Gottwald, the AK 912-63 TR. This is similar to the front six axle section of the main crane, but without the four axle section at the rear. It has the Gottwald lowline cab fitted. It has special platform on the back so that the superstructure can be raised and fixed into position, regardless of whether the ground is level or not. This crane was built for Mammoet/Al Jaber. Then it worked shortly for Franz Bracht, afterwards for Interlift (UK) and is now back in the UAE with Al Jaber.

The third crane was built in 1987/88 for Walter Wright in Australia. Only the main carrier section and superstructure were built at the Gottwald factory in Düsseldorf, Germany, the rest of the crane, lattice masts etc. being built in Australia by Gottwald importer and crane manufacturer Favelle-Favco. What makes this particular crane unique among Gottwald heavy cranes is that it is right hand drive. Mammoet later bought Walter Wright and it was later sold to GH Heavy Lift in Saudi Arabia. They replaced it with a Demag CC 8800 in 2002, and is currently working for “Equipos del Centro” in Southern America.

All three cranes can have 113 m (370 ft) of main mast (107 m/350 ft with Maxilift), Maxilift and 95 m (310 ft) of luffing jib, but as described earlier luffing jib and maxilift cannot be rigged at the same time.

Q: 1.5.5 And what else did Gottwald build?

A: Worth mentioning also are some other Gottwald cranes:

Lattice boom cranes

AK/MK 1000/1200/1500

Firstly, the unique MK 1000-113 which was supplied to Sparrows (UK) in 1980. After “Grayston, White & Sparrow” (GWS) bought Sparrows, the crane was put up for sale. After the contract with an American company fell through, the crane was bought by Scott Greenham who immediately planned upgrading the machine to a MK 1200 but never had the actual rework done. When GWS bought Scott Greenham in 1987, the machine was back in GWS’s hands. GWS thought about of rating the crane up to a MK 1500 (1,250 metric tons—1,377 sht—maximum lifting capacity) but only had the work done a few years later. Meanwhile, the crane works with ALE.

It is a pedestal crane with a 3.3 m (11 ft) wide superstructure, which is pulled by a 6 axle Gottwald tractor, and on the rear a 5 axle Goldhofer trailer. Also the rear of the superstructure must be removed for transport. Both the tractor and trailer parts must be removed when the crane is operating as more ballast needs to be added. Another thing about this crane which makes it different is that the winches are diesel electrically powered instead of the more usual diesel hydraulic power. The crane is also equipped with a Maxilift.

Additionaly, Gottwald built the upper carriages of two AK 1200 (called AK 1000 S) that are working as a stationary harbour cranes in France with a heavily modified boom system and ballast - one in Evry near Paris.

AK 680

Then there are the AK680 and AK450 cranes.

Of the AK 680, two were built, one very similar to the AK 850 (AK 680-1) and one on a semitrailer configuration which was the 6 axle Gottwald tractor at the front and a 4 axle Scheuerle bogie at the rear (AK 680-2).
The “conventional” one was built in 1980 for Scott (including a Maxilift). When “Grayston, White & Sparrow” (GWS) later took over Scott Greenham the crane became part of the GWS fleet. After Rentokil Initial bought GWS, the heavy cranes were sold to Sarens (Belgium) and smaller machines to Ainscough. Sarens had the crane heavily rebuilt and refurbished in 2001. The most obvious feature of the rebuild is the new style Demag driver’s cab. Since the rebuild it has been re-classified as AK 680-3 internally.

The semitrailer crane was supplied new with maxilift equipment to Stanley Davies in 1979. Since Stanley Davies worked closely together with Hewden Stuart, the crane was run in Hewden Stuart livery. When the cran crashed on a job with Maxilift equipment, the insurance company involved sold the cran to Schmidbauer who kept the maxilift equipment for their AK 850 when they sold it to Tecmaco (Argentina). Tecmaco is a subsidiary of Sarens (Belgium) and some years later, the crane came to Sarens itself. Like the MK 1000, this crane uses a 6 axle Gottwald tractor, but bogie only has four axles. After some overhaul and maintenance work, the crane is now called “AK 680-4” within Sarens.

In the course of time, both AK 680 received reinforced 18 m (59 ft) boom sections but presumably also kept the old ones. Furthermore there's proof that Hewden Stuart rigged the crane with a 107 m (351 ft) luffer on one job. This is 12 m (40 ft) longer than the official specification of 95 m (311 ft).

MK 660

The MK660 is a rather old design from the seventies, able to handle 650 metric tons (716 sht) of load. One crane was built in 1976/77 for Van Driessche in Belgium. After a while with Fostrans in France, the crane went to Peyrani in Italiy. This company is using it currently in Lybia.

MK 650

Contratry to its name, the MK650 could “only” lift 500 metric tons (550 sht). Of this type, three cranes were built: One of these was delivered to Stoof, Breda, NL. It was later sold at first to Cochez (F) and later to a chinese company.

The secound crane was built as a MK 650-68 for Schmidbauer in Munich in 1972, where it was as “Olympiakran” (olympic crane), due to the date of its delivery. The crane was always transported with the help of a four-axle Faun-Tractor and rearward three-axle module, but it could be done both in a semitrailer configuration or the crane being pulled as normal trailer with the help of a second three-axle module in front of the crane. Later the crane was to Van Seumeren and from there to somewhere in Marokko around 1990/91.

The third crane was built for Sarens in a semitrailer-configuration with a four-axle module a the rear. The crane was pulled by a six-axle MOL tractor. The crane went to Sarens/UK (known as “Curtis” then) after that and now works for Peyrani of Italy.

MK 600

The MK600 was originally designed as a 400 t crane (440 sht), but reportedly, these cranes have handled so much as 550 metric tons (600 sht). Van Driessche of Belgium owned a MK 600, that was later sold to Naber in Jordan. As of October 2010, the crane is still working.

A secound MK 600 was sold to Toense. The crane went from there to Lavis Stahlbau and later to Steinmüller, a South African contractor.

Furthermore, for Sparrows (UK) and Buzzichelli (Italy, 1972) a MK 600-88 each was built.

Another 600 was shipped to Ponticelli in France. Probably after a revision by Gottwald, the crane was cleared for a higher capacity and called “MK 655 S” internally. (But also the reference “MK 650 S” may be heard sometimes.)

MK 500

The MK500 was originally designed as a 350 t crane (385 sht). One was built in the late 60s as MK 500-88 for Van Twist in Dordrecht, NL.

A second crane was built for IMO Merseburg in the former GDR geliefert. This crane was sold in 1991 to Avi Cranes in Israel an is now used by Isa Khoury.

AK 450

Only two were built.One in 1983 for Franz Bracht who still have it today.

The second was built in 1987 for the former East German firm “Kombinat Kernkraftanlagenbau Dresden“ (KKAB, “Nuclear Facilities Construction Combine”). After that the crane worked for Breuer, and after their closure went to work for Mobi-Hub in Berlin, Germany. In 2002 (?) it was involved in a bad accident on a job in Berlin and was heavily damaged. Afterwards it was rebuilt by Köhler Kranservice and today works for Bracht too.

Markus Wienand has compiled some photos and additional technical details of the AK 450s on his website.

AK 300/400

The only AK400 was built by Gottwald as an AK 300-98 for Toggenburger in Switzerland. As a special feature, this crane could be transported directly on rails with the help of four three-axle bogies.
Later, this crane was sold to Toense and from there went to Franz Bracht, where it was upgraded to an AK 400-98. After a while, this crane was first sold to Johnson and South Africa and then to Hong Kong. The current state of the crane is unknown.

AK 350, AK 350/270, MDC 3500, MK 350

Gottwald built three 350 t (385 sht) cranes in total that were all unique to some degree. First, there was a AK 350-83 that was supplied to Sankyu, Japan. It is still there but reportedly has a new owner.

The second crane was supplied to the East German firm “VEB IMO Merseburg”. This company used to operate a AK270 before, but this crane was badly damaged in a traffic accident. Due to the shortage of western currencies in the GDR, the decision was made to buy only the base machine of a AK350 an re-use the boom sections of the AK 270. According to this, Gottwald only supplied the base machine an adaptors for the boom and counterweight. (Because of this, this crane is often referred to as the “AK 350/270”.)
Later, the crane was bought by van Seumeren who had it rebuild by Huisman to a “MDC 3500”. This included a new main boom with a larger cross section (while the old AK 270 main boom was rworked into a luffing jib) and a hammer-shaped heavy-load top as well as a derrick mast. Contrary to common practice, this mast isn’t built in the usual lattice style but made out of sheetmetal, making it look like a large A frame.
After some time of unknown ownership, the crane was finally working for Sarens in Mexcio, were it was heavily damaged in a traffic accident. Sarens is currently working on rebuilding the crane.

The third crane was a MK 350-84 that was shipped to South Africa. It is said to work as an harbour crane there. The crane lacks a drive for the undercarriage and is equipped with double tyres on all axles. (Therefore, one should expect a “MK 350-88” designation.) Furthermore, the upper carriage is very different form the other to 350 t cranes.

In general, it can be said that the AK 350 does look much like the AK 450 – even the boom parts have the same dimensions. Gottwald also thought of building a Maxilift system for the AK 350s which would have required an additional winch on the 26 m (85 ft) derrick mast, but it was never built.

Telescopic boom cranes

AMK 600-93

Gottwald made several telescopic cranes apart from the AMK 1000-103, such as the unique AMK 600-93. It was built in 1986 for Franz Bracht. It later worked for Krandienst Dresden (KTD) who sometimes used it with a luffing jib from a Liebherr LTM 1800. It now works for Sider Piombino in Italy, where it is again for sale right now. But the luffing jib remained with KTD, was used on a Liebherr LTM 1800 and was sold later together with the crane to Demag. The current status of the jib is unknown. (See also: entry on the AMK600 in the Identification Manual. (German only))

AMK 400/500

The AMK400/500 cranes were similar in appearance. There were four AMK 400-93 cranes built.The first was built in 1982 for Riga Mainz. It was replaced by the AMK 1000-103 in 1985 and sold to Colonia (Cologne, Germany) and then to Tecmaco. It was redesignated AMK 500-93. It was later fitted with maxilift which encreased lifting capacity at medium and large range. (See also: entry on the AMK 600 in the Identification Manual. (German only))

The second crane was also built in 1982 for Hewden (UK) and later sold to Long Hook in Taiwan. For this crane Gottwald built the mast transpoter AMK 400-73 TR. This is equipped with a cradle for holding the mast and also for it to be raised and fitted to the crane when on rough ground. (See also: entry on the AMK 500 in the Identification Manual. (German only))

The third example was build in 1983 for Toense. Then in 1988 it was sold to Interlift / Al Jaber and moved to England. Later it was moved to the UAE and then in 1994 it was sold to Al Mojil in Saudi Arabia. (See also: entry on the AMK500 in the Identification Manual. (German only))

The fourth crane was built in 1984 for Al Jaber and was equipped with extra radiators for operating in desert conditions. After the crane worked for about three months in Germany for Bracht (With Bracht signs but Arabian license plates!) and then Interlift in England, the crane is now back with Al Jaber. (See also: entry on the AMK 500 in the Identification Manual. (German only))

The AMK400–600s are different to all of the other Gottwald cranes discussed here in that the supports (outriggers) are transported on the main carrier. All of the others need to be removed and transported separately.

Gottwald built many other cranes also, but we are only looking at the best known ones here

Q: 1.8.1 Can the AMK 1000 really lift 1,000 t?

A: No. In order to achieve its maximum lifting capacity, a special, short heavy load mast is required. This was never built. With the existing telescopic mast the AMK1000 reaches stroke loads which are about the same as a 350 t crane. (385 sht)

Of course, all other aspects discussed in the “How realistic are stroke (maximum) load figures?” section apply too.

Q: 1.9.2

A:

Q: 1.10.1 What is the largest crane ashore?

A: The largest ashore crane is the “MSG-50” that Mammoet designed and built to their own needs and ideas. It is a “ringer crane”. This is a crane that runs on a circular rolling or rail track (in this case with a radius of 30 m (~100 ft)) to both operate and slew.

The ring creates a larger supporting base and better conditions for the main and derrick mast in relation to the supporting base. The crane has a maximum lifting capacity of 3,070 metric tons (3,384 sht), but the main disadvantage is that it cannot move once it is rigged. (Theoretically both MSG-50s could be combined to create an even larger crane).

The Mammoet PTC (Platform Twinring, Containerised) is also an amazing crane. Designed and built by Mammoet it is also a ringer with a maximum lifting capacity of 1,600 metric tons (~1,750 sht). The remarkable thing about this crane is that when it is de-rigged for transportation, every part fits into either a 20ft- or 40ft-container, so can be easily transported worldwide.

Q: 1.10.3 What is the biggest crane that can be drive itself on the road?

A: It’s a little difficult to give a answer that is 100% correct. First of all, there are the AK 912s that can lift 1,200 metric tons (1,322 sht) when working with its maxilift system.

Second, there’s the MK 1000/1500-113 that was only rated at 1,000 metric tons (~1,100 sht) when it was built in 1980. But later, it was upgraded to 1,250 metric tons (1,377 sht). Furthermore, this crane isn’t a “real” mobile crane, since it has several features of a pedestal crane.

Meanwhile, another crane has entered the top group: the Liebherr LTM 11200-9.1 which was introduced on Bauma 2007 and can also lift 1,200 metric tons.

Q: 1.10.5 Are there any more noteworthy cranes?

A: Of course. For example, there’s the largest tower crane in the world, the Krøll K-10000. (Also known as the “Kroll K-10000”.) This crane can lift 120 metric tons (264,000 lb) at the tip of a 100 m (330 ft) jib. Additional, there is an theoretical capacity of 240 metric tons (528,000 lb) to a maximum reach of 44 m (144 ft), but such lifts have to engineered individually by the manufacturer. Krøll even offers a special version with 360 metric tons (794,000 lb) at 61 m (200 ft).
The crane can reach a maximum lifting height of 86 m (282 ft). An additional special feature is the possibility to mount a “normal-sized” tower crane on top of the K10000’s tower, serving as an auxiliary crane.

Krøll of Denmark has built around 8–10 cranes of this type and sold them to the USA and the former Soviet Union. One of the Russian cranes was sold to van Seumeren in the 90s. This should be the same that is now with Mammoet.

You can find more facts and photos at http://www.towercrane.com.