Arcan­ge­lo Sas­soli­no and the Ital­ian School of Engineering

Arcangelo Sassolino and the Two Souls of the Italian School of Engineering

In this essay I inter­weave art, sci­ence, engi­neer­ing, phi­los­o­phy, mate­ri­als and forms. The text focus­es on con­crete and how dur­ing the twen­ti­eth cen­tu­ry the Ital­ian School of Engi­neer­ing has inter­pret­ed this mate­r­i­al to cre­ate works of art accord­ing to two dif­fer­ent approach­es: the nat­u­ral­ist approach and the pos­i­tivist approach. To more eas­i­ly under­stand the dif­fer­ence between the School’s two souls, which fra­ter­nal­ly coex­ist­ed, I use the work of an Ital­ian artist, Arcan­ge­lo Sas­soli­no. I first frame his work, which is that of an artist-engi­neer, as evi­dent in his instal­la­tion at the Venice Bien­nale 2022; then, through the analy­sis of oth­er pre­vi­ous works, I show how resis­tance by form (nat­u­ral­ist approach) and coac­tions (pos­i­tivist approach) are always present in his pro­duc­tion to address the sta­bil­i­ty and strength of materials.

An Artist-Engineer

Arcan­ge­lo Sassolino’s last work was exhib­it­ed at the 2022 Venice Bien­nale with the title Diplo­maz­i­ja Astu­ta. It is not entire­ly clear what the title of the work — astute diplo­ma­cy —means. The work was pre­sent­ed in the Biennale’s Mal­ta Pavil­ion rather than the Ital­ian, as he won a com­pe­ti­tion announced by the Mal­tese gov­ern­ment to seek both the cura­tors of the Mal­ta Pavil­ion and the work to be exhib­it­ed with­in. The work is a homage to the Behead­ing of Saint John the Baptist of 1608, a paint­ing by Michelan­ge­lo Merisi da Car­avag­gio placed in the Co-Cathe­dral of St. John, Val­let­ta, Mal­ta. Car­avag­gio arrived in Mal­ta after killing a man in Rome, pos­si­bly his rival in love. A boun­ty was lev­elled to hand him over to the judges who would cer­tain­ly con­demn him to death. Car­avag­gio fled to Naples and then to Mal­ta aboard a ship of the Order of Knights of St. John. Pro­tect­ing him was Alof de Wigna­court, the Grand Mas­ter of the Order. Wigna­court knight­ed Car­avag­gio and in return obtained for Mal­ta the exclu­sive work of one of the most bril­liant painters of all time. Car­avag­gio pro­duced at least three paint­ings in Mal­ta: Behead­ing of Saint John the Bap­tist and Por­trait of Alof de Wigna­court and his Page (lat­er sold and now housed in the Lou­vre); and final­ly, Saint Jerome Writ­ing, which remains in Mal­ta after a theft and return. Caravaggio's time in Mal­ta was short-lived, but there is no doubt that Alof de Wigna­court car­ried out an oper­a­tion of ​“astute diplomacy”. 

The con­text of Caravaggio's Behead­ing is dark. There are sev­en sub­jects in the paint­ing: the Bap­tist, the jail­er, the exe­cu­tion­er who is about to enact the final blow, a young woman car­ry­ing the bas­ket in which she will col­lect the head, an elder­ly woman dis­traught at the hor­ror and two pris­on­ers watch­ing from behind the grates. The light strikes only the pro­tag­o­nists; they are the ones mak­ing the light; then the light scat­ters upon the sur­face of the floor.

Sassolino’s immer­sive instal­la­tion, not unlike Caravaggio’s paint­ing, is also dark. There are sev­en tanks filled with water. Inside these huge ves­sels fall, in the same num­ber as the pro­tag­o­nists in the paint­ing, sev­en bands of white light com­ing from above, how­ev­er it is not light, but molten steel; he turns steel into light [ 1 ].

Sas­soli­no notes that ​“The emp­ty dark­ness of that wall, of those stones, of every­thing inan­i­mate – in Caravaggio’s paint­ing, that void seems to be the very con­di­tion of the scene, what makes pos­si­ble the vibrant, throb­bing light that makes those bod­ies live and move. This rad­i­cal con­trast between light and dark­ness makes the scene into some­thing that hap­pens before our eyes, and not mere­ly some­thing that will hap­pen or has already hap­pened. It is this con­trast that inter­ests me, or rather the idea that only through the con­flict and unre­solved ten­sion of forces we can see, even if only for an instant as a blind­ing light, the ori­gin of things—an ori­gin that, com­ing from noth­ing and des­tined to return into noth­ing, exists only in the ​‘here and now’ of its appear­ance. An ori­gin that appears and that at the very moment of its appear­ance is no longer there [ 2 ]. What I am try­ing to cap­ture is the change of state, that instant in which some­thing is becom­ing some­thing else, that ener­gy and pow­er that exist in the flash of absolute insta­bil­i­ty between the moments of equi­lib­ri­um that are the before and the after”.

Only through a change of state, and thus only in liv­ing time, does steel become light. Molten met­al is incan­des­cent; when poured it becomes a white beam of moving—liquid—light. On con­tact with water, steel hiss­es, cools and dis­pers­es to the bot­tom, retreat­ing into dark­ness [ 3 ].

Sas­soli­no adds, ​“I want to free met­al from that closed form, to expose its lumi­nous liq­uid ori­gin. Once melt­ed, met­al is no longer sim­ply sta­t­ic, no longer some­thing that mere­ly exists, unchang­ing – instead, it expands with­in a chrono­log­i­cal dimen­sion of appear­ance and dis­ap­pear­ance: it becomes time itself. Steel is cre­at­ed only at very high tem­per­a­tures, and when ener­gy and heat bring it back to its orig­i­nal liq­uid state, it glows with red-hot light; it becomes stol­id hard­ness only when that light goes out. Only in the change of state, and there­fore only in liv­ing time, does steel become light.”

Met­al is trans­formed by an induc­tion process, like that of the new gen­er­a­tion cook­ing stoves with­out open flames. The steel pass­ing through the mag­net­ic field goes from zero to 1500 degrees in half a sec­ond. The melt­ing is repeat­ed in a 6‑minute cycle. 

Dur­ing the sev­en months of the Bien­nale 25,000 kg of steel will have been melt­ed. This is an expen­sive but con­cep­tu­al­ly ​‘respon­si­ble’ project: the work ulti­mate­ly achieves Car­bon Neu­tral­i­ty. Green­house gas emis­sions have been reduced to a min­i­mum, for exam­ple by using ener­gy from renew­able sources and by recov­er­ing the steel, which will be re-melt­ed and then recy­cled (at 80%) in a local pro­duc­tion facil­i­ty. A vol­un­tary inter­na­tion­al stan­dard has been applied and the car­bon diox­ide equiv­a­lent emis­sions pro­duced are cer­ti­fied by a third-par­ty audit. Addi­tion­al emis­sions are off­set by a for­est pro­tec­tion project. 

The off­set­ting process (sim­pli­fied): if there is a por­tion of CO2 in the pro­duc­tion process that is incom­press­ible and despite all the pre­cau­tions and the use of renew­able sources, there is a resid­ual, to bal­ance this resid­ual a CO2 cred­it is pur­chased on the mar­ket and in prac­tice, anoth­er CO2-absorb­ing project is financed. In this case the cred­its used to bal­ance the 81 resid­ual tons of CO2 from Sassolino’s project are gen­er­at­ed by the Ntaka­ta Moun­tains REDD project, launched in May 2017 in Tan­za­nia, Africa, which involves local com­mu­ni­ties engaged in pro­tect­ing their vil­lages' for­est reserves. This, too, is ​“astute diplomacy”.

Sas­soli­no con­cludes that ​“This is a work about con­tin­u­ous loss, about the impos­si­bil­i­ty of hold­ing back, about the inex­orable and unstop­pable flow of all things. But it’s also about the fact that being is only revealed in van­ish­ing, that light is an evanes­cent inter­val of dark­ness. Some­thing keeps dis­si­pat­ing, con­sum­ing, yield­ing; the molten drops cease­less­ly appear, fall, and van­ish. I am try­ing to scan time – that which both cre­ates being and con­sumes it – through some­thing equal­ly elu­sive. Maybe mine is, at its core, a work about the open wound that is life. Why can’t sculp­ture flow like time instead of being a cold, rigid mono­lith devoid of the vital ener­gy that pro­duced it? Instead of fix­ing the instant of the pas­sage, mak­ing it once again some­thing sta­t­ic, I show the pas­sage itself, the appear­ance and the dis­ap­pear­ance, the glow­ing, ephemer­al lim­it that divides and con­nects the twin dark­ness­es of the before and the after”.[1]

To cre­ate this poet­ic pas­sage (appear­ance and dis­ap­pear­ance), Sas­soli­no works like an engi­neer, but no engi­neer could ever do what he does.[2] Sas­soli­no is not trained as an engi­neer; his train­ing his­to­ry is rather anom­alous. He was born in 1967 in Vicen­za, Italy, where he lives and works. In the late 1980’s he enrolled in a degree pro­gram in engi­neer­ing at the Uni­ver­si­ty of Pad­ua. But life took him else­where, first to the Unit­ed States, as a toy design­er where his 1989 patent, Com­pound­ed Poly­he­dron for Abil­i­ty Games, piqued the curios­i­ty of a New York-based Japan­ese com­pa­ny. It was in New York that Sas­soli­no dis­cov­ered his incli­na­tion for art and trained at the School of Visu­al Arts. He then returned to Italy and moved to Pietrasan­ta, near Mas­sa, where he began sculpt­ing mar­ble, and final­ly back home, where he start­ed a full-fledged work­shop with­in which he gen­er­at­ed his artis­tic engi­neer­ing works.

Sas­soli­no had unknow­ing­ly inher­it­ed the DNA of the Ital­ian School of Engi­neer­ing. In Octo­ber 2020 he was award­ed an hon­orary degree in Con­struc­tion Engi­neer­ing-Archi­tec­ture by the Uni­ver­si­ty of Rome Tor Ver­ga­ta, where the lessons of the mas­ters of Ital­ian engi­neer­ing would have found their place. In receiv­ing this hon­orary degree Sas­soli­no can be seen as the embod­i­ment of the two souls of the Ital­ian School of Engi­neer­ing based on two approach­es: one nat­u­ral­ist and one pos­i­tivist. Specif­i­cal­ly, the nat­u­ral­ist approach is based on resis­tance by form, while the pos­i­tivist approach is based on resis­tance by coac­tion. It is a jux­ta­po­si­tion that repeats between nature and tech­nique, between nat­ur­al and artificial. 

The Two Souls of the Italian School of Engineering

The oppo­si­tion between nature and tech­nique maps its way through the his­to­ries of phi­los­o­phy and sci­ence; it impas­sioned Aris­to­tle and it coursed through Descartes' pos­tu­lates. Nature is defined as ​"oth­er than man", it is by def­i­n­i­tion in oppo­si­tion ​‘to’, and to begin to under­stand the two souls of the Ital­ian School of Engi­neer­ing it is nec­es­sary to face the pos­i­tivist approach in order to bet­ter under­stand the nat­u­ral­is­tic one.

Dur­ing the 20^th cen­tu­ry the goal of all Ital­ian struc­tur­al design­ers was to opti­mize the behav­iour of the mate­r­i­al. The mate­r­i­al to be opti­mized was pre­dom­i­nant­ly con­crete because it was the only read­i­ly avail­able mate­r­i­al. Italy has no iron mines; there­fore the coun­try pro­duces very lit­tle steel. Instead, there is an abun­dance of cement marl quar­ries. Clay and lime­stone quar­ries are ubiq­ui­tous in Italy. Cement is Italy’s main kilo­me­ter-neu­tral material. 

Rein­forced con­crete, in all its forms and vari­a­tions, is Italy’s struc­tur­al mate­r­i­al of choice.

It arrived in Italy from France as it did in all Euro­pean coun­tries. Rein­forced con­crete was first used as a cheap­er sub­sti­tute for wood and steel. In the sec­ond half of the 1920s it was under­stood as hav­ing enor­mous, autonomous poten­tial, dif­fer­ent from that of oth­er mate­ri­als. The mar­riage of cement and steel cre­ates a com­pos­ite mate­r­i­al in which you can seam­less­ly vary the per­cent­ages of one and the oth­er, actu­al­ly obtain­ing mate­ri­als with dif­fer­ent behav­iours; chang­ing the ratio of mate­ri­als changes the strength, duc­til­i­ty, weight, elas­tic­i­ty[3]. And here­in are the two inter­pre­ta­tions the Ital­ian School gives to the mate­r­i­al: nature and technique.

The pos­i­tivist soul, which fore­grounds tech­nique, is con­vinced that it is pos­si­ble to improve mate­ri­als, to enhance them, to per­fect them beyond what nature offers. This opti­mism is cou­pled with the belief that the engi­neer must play an active role in the behav­iour of build­ings: the engi­neer must not be con­tent with solu­tions found in nature but invent more effi­cient mod­els. The design­er must be God's helper, Nature's helper. Nature must be cor­rect­ed; mate­ri­als must be imbued with new enhanced capa­bil­i­ties. Struc­tures, accord­ing to this log­ic, must be trained to respond to stress­es for which they are not suit­ed. And this can be achieved by impart­ing arti­fi­cial coac­tions to bod­ies, pre­vi­ous­ly deter­mined by cal­cu­la­tion, capa­ble of cor­rect­ing the nat­ur­al equi­lib­ri­um state of the struc­tures them­selves. One defin­i­tive appli­ca­tion of this idea is pre­stress­ing: pre­stress­ing teach­es con­crete to resist ten­sile stress­es, stress­es that con­crete would not be able to with­stand but which, once pre­stressed with ten­sile steel, it can eas­i­ly han­dle by loos­en­ing the ini­tial prestress.

Con­verse­ly, the nat­u­ral­ist approach argues that it is not nec­es­sary to teach struc­tures how to behave. Struc­tures should be left free to adapt spon­ta­neous­ly to loads while also mak­ing up for any gaps in knowl­edge on the part of the design­er. This belief in the inher­ent resources of nature leads to a clar­i­fi­ca­tion of the engineer's role: the engi­neer should observe nature, study it, inter­pret it, under­stand it, not nec­es­sar­i­ly imi­tate it but cer­tain­ly be in tune with it. 

Nat­u­ral­ists are skep­ti­cal about the pos­si­bil­i­ty of math­e­mat­i­cal­ly inter­pret­ing, at the desk, the response of the struc­ture; there­fore, they rely on stress cal­cu­lat­ing machines, that is ​'small-scale mod­els' that are sub­ject­ed to load tests in the lab­o­ra­to­ry. In using the small-scale mod­el as a tool the engi­neer only needs to learn to read nature's respons­es: it is nature that will explain to the exper­i­menter how it will behave at full scale. [4]

It is now clear how both posi­tions were equal­ly stim­u­lat­ing to Ital­ian engi­neers. The nat­u­ral­ist approach was man­i­fest­ed through the work of engi­neers like Pier Lui­gi Nervi and Ser­gio Mus­me­ci who sought the answer to their problems—though in very dif­fer­ent ways—in the obser­va­tion of nat­ur­al forms. Ric­car­do Moran­di, on the oth­er hand, did not pas­sive­ly wait for the inter­ven­tion of nature but imme­di­ate­ly imple­ment­ed those arti­fi­cial coac­tions capa­ble of ensur­ing more favor­able dis­tri­b­u­tions of inter­nal stress­es and is why he pro­mot­ed, at all lev­els, with unwa­ver­ing com­mit­ment, the spread of the pre­stressed concrete. 

Nervi defined and worked with resis­tance through form. Fer­ro­ce­ment, the mate­r­i­al he invent­ed dur­ing World War II, was excel­lent for shap­ing, curv­ing, and bend­ing because of its work­able thin­ness. Nervi nev­er designed orig­i­nal sta­t­ic organ­isms in terms of bal­ance, he always used tra­di­tion­al domes and vaults – sta­t­i­cal­ly sim­ple. What he invent­ed was the way to build them; he broke down his domes into thou­sands of small pieces, which he then recon­nect­ed like a huge three-dimen­sion­al puz­zle. Nervi used small-scale mod­els to ver­i­fy forces and form because math­e­mat­i­cal ana­lyt­i­cal cal­cu­la­tions could not explain the nat­ur­al behav­ior of his struc­tures.[5]

On the oth­er hand Moran­di was a ​"God's Helper" engi­neer. He cor­rect­ed nature; he applied coun­ter­weights, added forces to bal­ance oth­ers, com­posed forces, forced the struc­ture into a dynam­ic, seem­ing­ly unsta­ble equi­lib­ri­um. If there was a thrust, he applied a coun­terthrust. In his most famous arch bridges the nat­ur­al thrust of the arch is off­set by the pres­ence of inclined struts that act the oppo­site direc­tion. The struts act as forces inward to the arch, cor­rect­ing the pres­sure curve. Most impor­tant­ly, he used pre­stressed con­crete. In his futur­is­tic sub­tend­ed tie-rod struc­tures, Moran­di not only used pre­stressed con­crete to con­struct beams and roofs, but applied tie-rods at the ends that deformed the beam in an oppo­site and sym­met­ri­cal way to the action of the exter­nal loads: Moran­di played with com­po­si­tion of forces, dynam­ic bal­ance, thrust and coun­terthrust[6].

Ser­gio Mus­me­ci also had a nat­u­ral­ist approach but a bit dif­fer­ent. For Mus­me­ci, every­thing revolved around form. Regard­ing resis­tance he had an entire­ly orig­i­nal way of think­ing. Mus­me­ci said, ​"In this prob­lem, what form answers opti­mal­ly? The form is not giv­en but must be cal­cu­lat­ed from the bound­ary con­di­tions of the prob­lem?" And he would set off in search of the lim­it form, a prob­lem that is eas­i­ly solved only in the sim­plest of cas­es. For exam­ple, the ​“lim­it arch”: if I have a mate­r­i­al with a cer­tain com­pres­sive strength and spe­cif­ic weight and I want to make an arch, there is a span beyond which it is not pos­si­ble to go. This lim­it span cor­re­sponds to a very spe­cif­ic shape that Mus­me­ci calls the ​"lim­it arch." The span of this arch can be cal­cu­lat­ed and is equal to Pi times the strength of the mate­r­i­al divid­ed by its spe­cif­ic weight. Con­crete resists 100 kg/square meter and weighs 2500 kg/metrocube: if we divide the strength with the spe­cif­ic weight it results in about 400 meters. Mul­ti­ply­ing Pi by 400 meters, the result is 1250 meters. This is a lim­it­ing span that can­not be exceed­ed by a con­crete arch and to which cor­re­sponds a def­i­nite shape that, in turn, cor­re­sponds to the func­tion: y=logcosx. If the arch has a weight to car­ry, the shape remains the same but the lim­it span is small­er: the shape is invari­ant.[7]

Mus­me­ci argued that the good struc­tur­al engi­neer does not cal­cu­late assigned shape but assigns shapes. The engi­neer must ​“cal­cu­late form”, not ver­i­fy an assigned form. The engi­neer should not design cal­cu­la­tion meth­ods to find the stress­es but should design the stress­es. For exam­ple, in his Basen­to bridge, since it is a con­crete mem­brane, Mus­me­ci designs uni­form stress­es in all direc­tions with a com­plete absence of flex­ur­al dis­tur­bances. And from this he cal­cu­lates form.

Sassolino’s DNA

These are just the main pro­tag­o­nists of the Ital­ian School. Two whole gen­er­a­tions of struc­tur­al design­ers have been con­di­tioned by these approach­es, but those who we do not hes­i­tate to call philo­soph­i­cal, human­ist and cul­tur­al­ly complex.

How does Sassolino's work help us under­stand these ways of pro­ceed­ing? How does he stand in rela­tion to these two souls of the School, and in what sense did he inher­it the DNA of both lines of thought?

To explore these ques­tions I refer to one of Sassolino’s ear­ly con­crete works—Unti­tled— that is on view at the Nation­al Gallery of Mod­ern Art in Rome (GNAM), next to a Cret­to by Alber­to Bur­ri, anoth­er famous Ital­ian artist who used con­crete [ 4 ]. It is a thin resis­tant vault by form with a pleat­ed shape that gives it enough iner­tia to remain hang­ing with­out chang­ing shape. It is like ​"the name­less vault" of Musmeci's Basen­to Bridge in Potenza.

This seems to be a nat­u­ral­ist approach. But how was this work made? Sas­soli­no took a sheet of poly­car­bon­ate and pre-stressed it with thread­ed bars, thus plac­ing it in co-action with the bars, cre­at­ing a coac­tion between steel and poly­styrene [ 5 ]. On the poly­styrene, Sas­soli­no arranged a thin elec­tro-weld­ed mesh care­ful­ly shaped to the folds of the pan­el that is pro­vid­ed with hooks to hang the fin­ished work. He then pro­ject­ed by hand against the pan­el, lying on the ground, an anthracite-col­ored, quick-set­ting cement mixed with fine aggre­gates and iron oxide. The pro­jec­tion of the com­pound gen­er­at­ed a sheet of cement of vary­ing thick­ness, three or four cen­time­ters, but thin near the edges [ 6 ].

When the set­ting is com­plete, pan­el and foil are placed ver­ti­cal­ly, and the poly­car­bon­ate is sep­a­rat­ed from the cement. The act of their sep­a­ra­tion is a tear – vio­lent. The poly­car­bon­ate pan­el resumes its state of still­ness, it is no longer in coac­tion, but its mate­r­i­al ten­sion, its co-action, has been trans­ferred to the cement sheet whose jagged edges for­ev­er record the vio­lence of the detachment. 

There is not only resis­tance by form. There is also the idea of solid­i­fy­ing the ener­gy stored by the com­pressed poly­car­bon­ate [ 7 ] In some sense this is the same oper­a­tion Sas­soli­no uses regard­ing oth­er works in which he is aid­ed by com­plex cal­cu­la­tions, con­duct­ed by expe­ri­enced engi­neers, that push his works to the ​“lim­it form”, just as Mus­me­ci loved.

For exam­ple, when he stretch­es chest­nut wood beams (Unti­tled, 2007) between the groans and slur­ries of the mate­r­i­al until they break [ 8 ] Or in the more recent Physis: two heavy bod­ies of gran­ite and con­crete, moved away and brought clos­er, in a dai­ly cycle, with a solar-pow­ered pis­ton, from 2022 part of the per­ma­nent col­lec­tion of Arte Sel­la, in the area of Mal­ga Cos­ta in Val di Sel­la, in Bor­go Val­sug­ana (Tren­to); and above all, Tem­po pie­ga­to, pre­sent­ed at Art Basel 2022 where—Sassolino says—"a glass is bent to the lim­it of its resis­tance: there is a con­flict in the act; some­how the mate­r­i­al is suf­fer­ing; it could not resist; the time is com­pressed into the sculpture." 

Resis­tance by form, typ­i­cal of a nat­ur­al approach, but also coac­tions between mate­ri­als and arti­fi­cial stress­es, indi­cat­ing a pos­i­tivis­tic approach. In short: works of art between nature and tech­nique, full of engi­neer­ing, full of the influ­ence of Ital­ian School of Engineering.