The property object of the declaration of property of cultural interest occupies an area of ​​2,538 square meters located on the corner of Valderribas and Sánchez Barcáiztegui streets), delimited on the outside by a period fence, formed in its main part by a stone masonry wall and brickwork, reinforced with pilasters to which the wrought iron grilles are attached.

The two entrances to the plot from the perimeter road are flanked by pilasters crowned with lanterns of an elaborate design by Antonio Palacios. The rest of the exterior enclosure is a tile brick wall.

The main construction, properly called the Engine Shed, has a rectangular plan in a north-south direction and is developed on a single level above ground level), except at the southern end, where a narrow mezzanine appears) with the control panels of the plant and auxiliary rooms. It has a rectangular floor plan 44.2 m long and 17.5 m wide (773.5 m²), with a wall height of 12 m and 16 m at the ridge.[1]​ The basement houses maintenance galleries for access to equipment and layout of pipelines. The entrance is through the gable or north wall through a windbreak introduced in a restoration carried out at the beginning of the century. Originally said north wall was built in a simple way, anticipating the case that its demolition was necessary for the expansion of the nave.[1]​.

The door is made of wood, double-leaf, and allows passage directly to the platform on which the generating set is located. This platform is located 52.3 m above the floor level of the ship. Access to the top of the engines is via three flights of stairs protected by a tubular iron railing.[1]​.

The facades are organized vertically, articulated from pilasters that coincide with the trusses of the roof structure. Between the pilasters there is a double alignment of window openings topped by lowered arches. Those on the lower level are large vertical windows with steel carpentry with grid layout. Those on the upper level are smaller and of similar typology. The building starts from the ground with a small masonry plinth "Plinth (construction)" cut by the large windows. The rest of the facades are made of exposed brick, except for the pilasters and false imposts plastered with lime mortar. The roof of the ship is made up of louvered steel trusses, of the Polonceau type), on which support straps "Strap (architecture)") and metal walls) supporting the board "Board (architecture)") that makes up the roof skirt&action=edit&redlink=1 "Skirt (Architecture) (not yet written)") of the roof.

Inside, the walls appear plastered and partially tiled with white tiles placed diagonally. The tiled parts are outlined with simple blue lines as borders, drawn with a decorative sense close to Viennese modernism") with tile borders with blue lines. In some sections of the wall, more complex decorative elements made of glazed ceramic with metallic reflections are arranged, as false capitals. machinery existing in the ship. The interior walls have variable thickness, using the horizontal stagger as support for the ship's bridge-crane.

The transformer building or body, attached to the south gable of the Engine Bay, is a narrow three-story rectangular building that gives the opportunity to project a more complex façade than the ship itself. Articulated vertically by pilasters, these end in pinnacles that exceed the height of the cornice. Here the order of openings is narrower than in the rest of the complex and the windows are grouped two by two, separated by narrow mullions. This façade is set back from Valderribas Street, delimiting a small access patio.

Above the roof balustrade appears the South gable of the Engine Bay, with a stepped profile, incorporating the Metro emblem. It has been restored in its outer envelope.

The office or administrative building is a rectangular block with a single bay "Crujía (architecture)") attached to the west side of the Engine Shed. It has three floors and a basement, focusing all the interest on the west façade, articulated vertically by pairs of pilasters that contrast against the exposed brick factory background and extend into pinnacles. The central body, which houses the entrances and the staircase, is slightly higher than the rest. The format of the openings and the façade treatment are similar to that of the transformer body, but here the windows are grouped three by three. It has been restored in its exterior envelope, with no notable elements of interest existing inside.

The personality of Antonio Palacios' architecture, capable of giving a coherent response to functional programs of a very diverse nature, but always preserving a perfectly identifiable imprint, meant that, for decades, the image of the Madrid Metro was associated with his figure. In the case of the Old Pacific Power Plant, its mark can be found in the ease and elegance with which it is able to organize large surfaces of facades, in the use of tiles for practical and at the same time decorative purposes in interiors or in the design of the locksmith elements, strictly functional in the work areas and more elaborate in the visible parts, such as the "Lantern (lighting)" lanterns included in the perimeter fence.

Decoration understood in the traditional way is reserved for very significant places: it rescues formal and decorative resources from past styles or those of the moment, such as references to neo-Mudejar in the use of brick and stone, producing the red and white bichrome characteristic of this style, as well as the use of the stepped pinion of the main façade. On the other hand, the influence of Viennese secessionist modernism can be observed, with a taste for stacked facades, windows organized in bands and segmented arches, very marked imposts that resemble capitals, decorative elements in parallel lines, all interpreted with their own personality.

In addition to its architectural envelope, from the point of view of the strict industrial heritage, the Pacifico Power Plant is one of the complexes that best preserves all the machinery and equipment of the activity, allowing a coherent and complete sample of it, from the buried fuel tanks, the fluid transport networks, the auxiliary tanks, the electrical energy production and transformation equipment, the complementary refrigeration and control facilities, the spare and maintenance material and the tools for the operators.

What stands out above all are the three large diesel engines, of 1500 HP each, and the alternators coupled to them for generating electrical energy, which were in operation from 1923 to 1972.

• - Annex: Industrial Heritage of Spain.

• - This article includes content derived from a provision relating to the process of protection, initiation or declaration of a cultural or natural asset published in BOCM No. 127 on May 29, 2012 (), which is free of known restrictions under copyright in accordance with the provisions of article 13 of the Spanish Intellectual Property Law.

• - Wikimedia Commons hosts a multimedia category on Pacific Engine Ship.

• - on YouTube.

The property object of the declaration of property of cultural interest occupies an area of ​​2,538 square meters located on the corner of Valderribas and Sánchez Barcáiztegui streets), delimited on the outside by a period fence, formed in its main part by a stone masonry wall and brickwork, reinforced with pilasters to which the wrought iron grilles are attached.

The two entrances to the plot from the perimeter road are flanked by pilasters crowned with lanterns of an elaborate design by Antonio Palacios. The rest of the exterior enclosure is a tile brick wall.

The main construction, properly called the Engine Shed, has a rectangular plan in a north-south direction and is developed on a single level above ground level), except at the southern end, where a narrow mezzanine appears) with the control panels of the plant and auxiliary rooms. It has a rectangular floor plan 44.2 m long and 17.5 m wide (773.5 m²), with a wall height of 12 m and 16 m at the ridge.[1]​ The basement houses maintenance galleries for access to equipment and layout of pipelines. The entrance is through the gable or north wall through a windbreak introduced in a restoration carried out at the beginning of the century. Originally said north wall was built in a simple way, anticipating the case that its demolition was necessary for the expansion of the nave.[1]​.

The door is made of wood, double-leaf, and allows passage directly to the platform on which the generating set is located. This platform is located 52.3 m above the floor level of the ship. Access to the top of the engines is via three flights of stairs protected by a tubular iron railing.[1]​.

The facades are organized vertically, articulated from pilasters that coincide with the trusses of the roof structure. Between the pilasters there is a double alignment of window openings topped by lowered arches. Those on the lower level are large vertical windows with steel carpentry with grid layout. Those on the upper level are smaller and of similar typology. The building starts from the ground with a small masonry plinth "Plinth (construction)" cut by the large windows. The rest of the facades are made of exposed brick, except for the pilasters and false imposts plastered with lime mortar. The roof of the ship is made up of louvered steel trusses, of the Polonceau type), on which support straps "Strap (architecture)") and metal walls) supporting the board "Board (architecture)") that makes up the roof skirt&action=edit&redlink=1 "Skirt (Architecture) (not yet written)") of the roof.

Inside, the walls appear plastered and partially tiled with white tiles placed diagonally. The tiled parts are outlined with simple blue lines as borders, drawn with a decorative sense close to Viennese modernism") with tile borders with blue lines. In some sections of the wall, more complex decorative elements made of glazed ceramic with metallic reflections are arranged, as false capitals. machinery existing in the ship. The interior walls have variable thickness, using the horizontal stagger as support for the ship's bridge-crane.

The transformer building or body, attached to the south gable of the Engine Bay, is a narrow three-story rectangular building that gives the opportunity to project a more complex façade than the ship itself. Articulated vertically by pilasters, these end in pinnacles that exceed the height of the cornice. Here the order of openings is narrower than in the rest of the complex and the windows are grouped two by two, separated by narrow mullions. This façade is set back from Valderribas Street, delimiting a small access patio.

Above the roof balustrade appears the South gable of the Engine Bay, with a stepped profile, incorporating the Metro emblem. It has been restored in its outer envelope.

The office or administrative building is a rectangular block with a single bay "Crujía (architecture)") attached to the west side of the Engine Shed. It has three floors and a basement, focusing all the interest on the west façade, articulated vertically by pairs of pilasters that contrast against the exposed brick factory background and extend into pinnacles. The central body, which houses the entrances and the staircase, is slightly higher than the rest. The format of the openings and the façade treatment are similar to that of the transformer body, but here the windows are grouped three by three. It has been restored in its exterior envelope, with no notable elements of interest existing inside.

The personality of Antonio Palacios' architecture, capable of giving a coherent response to functional programs of a very diverse nature, but always preserving a perfectly identifiable imprint, meant that, for decades, the image of the Madrid Metro was associated with his figure. In the case of the Old Pacific Power Plant, its mark can be found in the ease and elegance with which it is able to organize large surfaces of facades, in the use of tiles for practical and at the same time decorative purposes in interiors or in the design of the locksmith elements, strictly functional in the work areas and more elaborate in the visible parts, such as the "Lantern (lighting)" lanterns included in the perimeter fence.

Decoration understood in the traditional way is reserved for very significant places: it rescues formal and decorative resources from past styles or those of the moment, such as references to neo-Mudejar in the use of brick and stone, producing the red and white bichrome characteristic of this style, as well as the use of the stepped pinion of the main façade. On the other hand, the influence of Viennese secessionist modernism can be observed, with a taste for stacked facades, windows organized in bands and segmented arches, very marked imposts that resemble capitals, decorative elements in parallel lines, all interpreted with their own personality.

In addition to its architectural envelope, from the point of view of the strict industrial heritage, the Pacifico Power Plant is one of the complexes that best preserves all the machinery and equipment of the activity, allowing a coherent and complete sample of it, from the buried fuel tanks, the fluid transport networks, the auxiliary tanks, the electrical energy production and transformation equipment, the complementary refrigeration and control facilities, the spare and maintenance material and the tools for the operators.

What stands out above all are the three large diesel engines, of 1500 HP each, and the alternators coupled to them for generating electrical energy, which were in operation from 1923 to 1972.

• - Annex: Industrial Heritage of Spain.

• - This article includes content derived from a provision relating to the process of protection, initiation or declaration of a cultural or natural asset published in BOCM No. 127 on May 29, 2012 (), which is free of known restrictions under copyright in accordance with the provisions of article 13 of the Spanish Intellectual Property Law.

• - Wikimedia Commons hosts a multimedia category on Pacific Engine Ship.

• - on YouTube.