It was the year 1998, I was about to get married, and an excellent client, GML—part of the Peruvian engineering, construction, and real estate conglomerate Graña y Montero, now AENZA—was building the Larcomar shopping and entertainment center on the cliffside of the Miraflores district in Lima, at the end of Av. Larco, right where the traditional Parque Salazar was located.
At that time, I was the Head of Engineering at Técnicas Metálicas Ingenieros (TMI), and we had been pursuing business opportunities with the Graña y Montero group, which was not only constructing Larcomar but also, just across the avenue, building the Marriott Hotel (where my future wife was part of the supervision team) and, in the same block, the Parque Mar Tower, a twin building to the Marriott Hotel.
TMI was an engineering and construction company specialized in the fabrication and installation of steel structures and heavy industrial works. Over time, it became the sector leader, with the largest installed capacity in Peru, handling approximately 3,000 tons of steel monthly.
Our commercial efforts paid off, and GML’s project manager for Larcomar, Luis “Luchín” Vargas, called us in for a job that perfectly matched our capabilities: fabricating and installing three steel chimneys that would later be covered with glass by other contractors.
The fabrication workload posed no problem; each chimney contained approximately 17.5 tons of steel and accessories, making the total work volume just under 53 tons. However, the geometry was somewhat complex. The chimneys were elliptical, not circular, and the most challenging elements were the supports for the glass coverings to be installed after the structure was erected. These supports gave our detailing engineers more than one headache during fabrication.
As Head of Engineering, I oversaw the Proposals Department, and besides accounting for the geometric challenges and complexity of the support accessories, I faced an unexpected issue: the installation could not be executed using any crane available in the country.
Let me explain. A typical installation of heavy elements involves placing a crane as close as possible to the final position of the load to minimize the “lever arm” (the distance between the crane’s center of gravity and the load’s center of gravity). This allows the crane to lift the load more efficiently. If site conditions force the crane to be placed farther away from the load’s final position, increasing the lever arm, the crane’s lifting capacity is significantly reduced. This is basic physics: attempting to lift the same weight with a longer lever arm creates a tipping effect. No matter how powerful the crane's engine is, failing to respect the maximum load-to-lever-arm ratio will result in an accident. That's why every crane has a load chart that specifies the maximum allowable load based on the distance from the crane's axis to the load's center of gravity. This chart is known as the crane's "load chart."
Unfortunately, the site conditions at Larcomar prevented the crane from being placed close to the chimneys' positions, as the entire area was a post-tensioned concrete slab with three levels of parking underneath. One option was to shore up those three levels, but besides the unacceptable risk of positioning a crane and performing a maneuver on shored-up slabs, it was unfeasible to halt work in the basements for the time required to shore up, unload the chimneys on-site, position the crane, move it between each of the three final chimney locations, and finally remove the shoring.
The obvious alternative was to place the crane farther away, outside the post-tensioned slab area. This would require positioning the crane on the avenue separating the Larcomar and Marriott Hotel construction sites. Beyond the obvious issues of closing a road in Lima's most touristy district, there was a physical obstacle: the lever arm required was so large that no crane in the country (not only in terms of motor capacity but also size and weight) could perform the maneuver.
How do you price a job when you don't know how to execute it? A cynic might suggest "charge exorbitantly and hope the client declines." We considered that too. We analyzed the problem extensively with the installation team, and TMI met with GML to find a solution. Finally, an interesting alternative emerged: use a helicopter.
With this option on the table, as Head of Engineering, I was tasked with finding a provider. I met with Jorge Luis Infantas, Head of Installations, and together we visited the Army Aviation unit. We explained our needs to their commander, who, after some thought, confirmed that a helicopter maneuver was feasible and that they had the necessary equipment.
In my youthful naivety (I was 27 at the time), I asked if they had ever performed a similar maneuver. Without hesitation, the commander replied that they had installed the roof of the new Jockey Plaza shopping center using a helicopter.
I turned pale immediately and was grateful to be seated, as I almost fainted. We thanked the commander for his kindness, promised to stay in touch, and left. Walking to the parking lot, I told Jorge Luis, "The roofs of Jockey Plaza? I installed those… and no helicopter was involved." He turned pale as well.
To keep the story short, we ultimately contacted an American company, Erickson Air Crane (EAC), specialized in aerial crane operations using helicopters specifically designed for lifting, transporting, and placing heavy loads. These "aerial cranes" have two control cabins: one for the pilot and another, directly behind it, for the crane operator, who has full visibility of the load and controls for lifting, rotating, and even flying the helicopter for fine positioning of the load.
EAC was operating in the Peruvian jungle at the time, so we had to coordinate schedules, but the costs were extremely high. Like all cranes, an aerial crane charges by the hour, but in this case, for flight hours. We had to account for the time it would take the helicopter to travel from its base in the jungle to Lima and back.
Given the uniqueness of the operation, it was agreed that GML would directly cover EAC's aerial crane costs, while TMI's price for the installation was calculated based on the personnel and auxiliary equipment required for the maneuver, as jointly designed by TMI and EAC.
Helicopters, like any other aircraft, must evaluate their flight autonomy, which depends on the amount of fuel and the weight of the load. In this case, the weight of a single chimney was approximately equal to the aerial crane's maximum load capacity, even with minimal fuel. Considering that the helicopter had to take off from its base in Callao, reach TMI's plant to pick up each chimney, transport it to the installation site, maneuver it into its final position, and then return to Callao for refueling, it was imperative to reduce the weight to be lifted.
Calculations, including an appropriate safety factor, determined that each chimney had to be cut into three sections for transport and installation. This meant nine operations in total, and a quick and safe assembly system was required so that the aerial crane could place the second and third sections of each chimney onto the lower sections, ensuring proper horizontal alignment (to avoid rotational misalignment) as quickly as possible. Every extra minute consumed fuel, reducing flight autonomy and compromising the safety margin of the operation.
The assembly system was achieved using square-section tubes as "guides," placed at the base and top of the two lower sections. A safety zone was defined where a load that could not be correctly positioned in the allotted time could be deposited, allowing the aerial crane to detach from it and return to Callao to refuel before retrying the maneuver. Jorge Luis Infantas was placed in charge of overseeing the installation operation on-site, and only he could issue instructions.
The operation was scheduled for a Sunday, starting at 9:00 a.m. Permits were obtained from the General Directorate of Air Traffic (DGTA), and it was made clear that everything had to be completed no later than 5:00 p.m., as the DGTA only allowed the aerial crane to operate during daylight hours. Limiting hazardous operations such as installations to daylight hours is also a good practice, even with traditional methods.
On the designated Sunday, thanks to my fiancée's arrangements, I gained access to the Marriott Hotel construction site, where the highest floor slab was equivalent to just a sixth floor at the time, to witness the maneuver and take official photos.
As you can imagine, the permit process was not completed in time, and the first of the nine planned lifts took place late in the afternoon. The first section was successfully positioned just before 5:00 p.m.
Finally, everything resumed on Monday at 9:00 a.m. By then, normal work had resumed at the Marriott Hotel site, so I could no longer access the highest floor slab. Instead, the TMI senior management and I settled into the Social Club of Miraflores restaurant, placing chairs near the window. It was on the second floor, so the view wasn't as good as the day before, but it was still a fascinating and unforgettable spectacle.
One by one, the remaining sections were delivered… until one failed to fit properly. After several minutes without achieving a correct alignment, the order was given to deposit the problematic section in the designated safety zone. While the aerial crane refueled, the field team under Jorge Luis's command corrected the guides of the section meant to receive the load. After verifying that everything was ready, instructions were sent to the aerial crane to take off from its base and continue the operation.
The aerial crane lifted the load from the safety zone and successfully positioned it in place. The remaining sections were installed without further issues, and by the end, all three chimneys were complete.
Throughout my professional career, I've been part of truly remarkable installation operations. We've launched bridges weighing several tons over deep ravines, installed the Interbank trading room structure, erected the Puentes del Ejército bridges steel structures, one of the three (at least at the time) Loesche mills in the country, transmission towers over 185 meters high (the tallest structures in Peru), and countless complex, challenging, and hazardous operations. However, the installation of the Larcomar chimneys remains the most memorable and delicate operation I've had the privilege of participating in.
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