When attempting to compare and choose what to prefer — a truck crane or a knuckle boom crane, this is partly an attempt to compare incomparable objects — in other words, trying to compare the incomparable. However, at the same time, a modern knuckle boom crane is capable in many situations not only of replacing a truck crane, but also of offering more capabilities than a conventional truck-mounted crane. The specialists of our company have spent many years working at plants that manufacture both traditional crane installations and knuckle boom cranes, so let us entrust them with answering the question: «Which is better: a truck crane or a knuckle boom crane?». At the same time, we will clarify in which situations a truck crane is the better choice, and in which cases a knuckle boom crane is preferable.
Is it correct to compare knuckle boom cranes and truck cranes?
On the one hand, comparing these types of special-purpose equipment is not entirely correct, because despite similarities in design, these lifting mechanisms are not identical. On the other hand, a powerful knuckle boom crane designed to lift multi-ton loads is quite capable of providing serious competition to a traditional truck crane with a lifting capacity of 10–16 t.
There is another significant difference between these types of lifting equipment — the ranking principle. Truck cranes differ from one another by lifting capacity, i.e. the maximum load weight in tonnes that the crane can lift at the minimum outreach. The ranking system for knuckle boom cranes (KBC) is somewhat different — historically, KBCs are divided into series based on load moment, measured in tonne-metres ™. This refers to the maximum load moment value, i.e. the product of the outreach and the load weight.
In addition, in recent years there has been a growing trend to equip knuckle boom cranes (as a rule, micro and light-duty series) with an electro-hydraulic package, enabling operation from the vehicle’s electrical system. In the case of stationary installation of a KBC, operation from a 380 V power supply is possible. Some truck crane manufacturers also occasionally offer a similar option, but this is rather the exception than the rule.
A universal lifting mechanism
Like a truck crane, a knuckle boom crane can lift loads; moreover, the vehicle on which the KBC is installed is also capable of transporting cargo, whereas a truck crane does not have this capability. Modern competition in the lifting equipment market forces brands competing for customers to produce universal crane installations. Many manufacturers of knuckle boom cranes and truck cranes, in addition to the traditional hook suspension, also equip their machinery with a man basket, adapting the truck crane or truck-mounted manipulator to the functionality of an aerial work platform. However, such upgrades are not permitted under Ukrainian legislation.
According to crane equipment specialist Vsevolod Tymoshenko of MPP «Modus», the demand forecast for universal lifting mechanisms in 2019 was as follows: «We expect an increase in demand for multifunctional crane installations, because the modern customer wants to obtain more capabilities without increasing their own costs. European countries, which are more advanced in this respect, are gradually losing interest in traditional truck-mounted crane installations and are massively switching to knuckle boom cranes of various lifting capacities. Most knuckle boom cranes, for example in the FASSI (Italy) KBC range, can be used as truck-mounted aerial lifts, since the range of additional attachments includes man baskets for lifting personnel. There are also attachments such as timber grapples, pallet forks, buckets (grapples) for bulk materials, and more».Thus, a modern lifting mechanism is not only about lifting and lowering heavy objects, but also about transportation and functional work with them. The above-mentioned crane modifications into aerial work platforms are a real example of demand for universal special-purpose equipment.
However, there is also a downside — the price of a powerful knuckle boom crane or a universal truck crane. Unfortunately, the mass Ukrainian consumer is not yet ready to purchase a KBC or another universal machine instead of a conventional truck crane. There is another reason as well — performing a wider range of diverse tasks requires higher operator qualifications (in this case, the crane operator or the driver of a vehicle equipped with a KBC). In modern business, a company will not employ a crane operator, a loader, and an operator of a drilling rig or aerial platform to service a single unit of equipment. The increase in equipment cost and labour costs for its operation, as well as higher personnel requirements (in other words — total cost of ownership), are the main stumbling blocks hindering demand growth for medium-duty and heavy-duty knuckle boom cranes, as well as universal crane installations with extended functionality.
Compared to a truck crane, a KBC is more versatile special-purpose equipment, but its lifting capacity at minimum outreach, which averages up to 10 t across the market, is comparable at best to a 16-ton truck crane. However, one of the latest heavy-duty series models of Fassi HEAVY DUTY knuckle boom cranes in this class features an increased load moment of 160 tm and a lifting capacity of 30 tonnes, while the Effer brand has introduced a manipulator with lifting capacities of 63 t at minimum outreach and 19.3 t at maximum outreach. Nevertheless, prices for these products are still prohibitively high for the Ukrainian market, and business owners are not yet ready for such investments in fixed assets.
According to the specialists of MPP «Modus», the use of a KBC is justified in the following cases:
- Operations performed irregularly and without the ability for the owner of the vehicle with a KBC to plan routes in advance, involving lifting loads weighing from 1 to 10 t. The ideal buyer of a vehicle equipped with a KBC is a company with medium-scale logistics operations, for example, when a truck periodically waits to load construction materials. The owner of such equipment always has the opportunity to load the goods immediately after purchase and transport them to the storage or point of use. Please note that for large construction businesses it is more cost-effective to use a truck crane and five flatbed trucks, which will handle tasks more efficiently than five special vehicles equipped with knuckle boom cranes. At the same time, small and medium-sized businesses gain more benefits from using a knuckle boom crane installed on a truck.
- The second advantage of a KBC, making it more competitive compared to truck cranes, is the ability to operate in confined spaces. A truck crane in deployed position occupies significantly more space and requires more time to prepare for operation (boom deployment) than a knuckle boom crane (15–20 minutes are sufficient to deploy the manipulator). In addition, do not forget about overhead power lines, which interfere with truck crane operation. However, truck cranes have a significant advantage — the presence of counterweights for operational safety, whereas KBCs do not have them. Moreover, in order to reduce the cost of KBCs, customers in Ukraine typically refuse the installation of a load moment limiting system (in other words, overload protection). Additional advantages of truck cranes include higher lifting capacity compared to knuckle boom cranes, as well as greater maximum outreach and lifting height. Truck cranes are more complex to operate — working with them requires higher qualifications than operating a hydraulic manipulator boom.
- Alternative use of a KBC as a truck-mounted aerial lift is justified if such operations are infrequent. For regular personnel lifting, preference is given to traditional-design aerial work platforms. By analogy: professional photography requires serious camera optics, while taking a selfie or a quick amateur snapshot can be done with a camera integrated into a mobile device.
- Number of operating cycles. Where prolonged and monotonous work involving lifting and lowering heavy and oversized loads is required, with high dynamic and static loads and extended presence on a construction site, a truck crane is unquestionably the better choice. A KBC, by contrast, is designed for loading and unloading vehicles, after which transportation follows, during which the KBC is not in operation. The only type of KBC designed for a significantly higher number of cycles is the specialized knuckle boom crane for forestry operations.
