Hermosa–Duhat–Balintawak Transmission Line

The Hermosa–Duhat–Balintawak Transmission Line began construction in September 1993 and went into service in June 1994.[1][2] Originally commissioned by the government-owned National Power Corporation (NAPOCOR), it is now operated and maintained by privately-owned National Grid Corporation of the Philippines (NGCP). Prior to the completion of the line's cut-in connection to Meralco Duhat substation, it was a one-part power line and had direct tap connection. It originally had a length of 91 km (57 mi) from 1994 to November 16, 2009. The line was extended to 91.59 km upon the completion of its cut-in connection to Duhat substation on November 2009 and then reduced to 87.54 km (54.39 mi) when its San Simon–Pulilan segment was relocated along North Luzon Expressway (NLEx) in March 2011. It uses steel poles on most of its portions, with lattice and portal towers are located on some portions of the line. Portal towers are used on portions of the line where it intersects with another power line.

The transmission line passes through the cities of Quezon City, Caloocan, and Valenzuela in Metro Manila, Meycauayan and Malolos in Bulacan, and San Fernando in Pampanga and municipalities of Marilao, Bocaue, Balagtas, Guiguinto, Plaridel, Pulilan, and Calumpit in Bulacan, Apalit, San Simon, Santo Tomas, Bacolor, Guagua, and Lubao in Pampanga, and Hermosa in Bataan. It is located within the service area of NGCP's North Luzon Operations and Maintenance (NLOM) Districts 5 (West Central Plain), 6 (South Central Plain), and 7 (National Capital Region).

Hermosa–Duhat

Two visible incomplete design lattice towers (56 and 57) located near Santa Cruz Bridge in Lubao, Pampanga. Nearby is steel pole 55 that anchors to lattice tower 56.

The transmission line starts at Hermosa Substation and parallels with the Jose Abad Santos Avenue until San Fernando Exit of NLEx. Upon passing the Bataan–Pampanga welcome arch, it enters Pampanga and continues straightforward. The line intersects with Hermosa–Guagua in Lubao, Mexico–Hermosa in Lubao, Guagua, Bacolor, and San Fernando, and Hermosa–Malolos–San Jose lines in Guagua while running parallel with the said avenue. Upon approaching Santa Barbara Bridge, it will utilize the eastern side of the avenue. The power line then passes through lahar-filled Bacolor and enters San Fernando upon passing the city's welcome arch. After Villa del Sol in Magliman, San Fernando, the line again utilizes the western side of the road. It then passes through Lazatin and Dolores Flyovers and various establishments within San Fernando, and enters the western side of NLEx, where it runs parallel to it until Smart Connect Interchange.

After entering NLEx, it intersects with Mexico–Hermosa line for a fifth and final time. It continues on a straight route, intersecting with Mexico–Balintawak and Mexico–Calumpit lines in Santo Tomas, and passes through San Simon Exit (where the line left the NLEx alignment prior to the relocation of its San Simon–Pulilan section in 2011).[lower-alpha 6] The line continues on a straight alignment and runs parallel with Candaba Viaduct where it crosses Pampanga River and passes through rice paddies and swampland in Apalit, Calumpit, and Pulilan. It then enters Bulacan after passing the former location of a billboard located near steel pole 271, passes through Pulilan Exit (where it reentered the NLEx alignment from 1994 to 2011), and continues straightforward. The power line intersects with Hermosa–Malolos–San Jose in Plaridel and Mexico–Balintawak lines in Guiguinto for the second time, passes into Balagtas Interchange, Bigaa and Santa Maria Rivers, Bocaue Exit, Bocaue Toll Plaza, and Ciudad de Victoria Interchange. In the future, the line will intersect with Hermosa–San Jose 500,000-volt line. It turns left into Meralco Duhat Substation a few meters after passing Ciudad de Victoria interchange, where the line's Hermosa–Duhat section ends.

Duhat–Balintawak

Steel pole 479 (of suspension or triangle design) situated along NLEx near Canumay Overpass Bridge in Valenzuela.

The line turns left upon entering NLEx, continues on a straight direction, and enters Metro Manila after steel pole 465. It then utilizes the eastern side of NLEx after steel pole 488, leaves the expressway at Smart Connect Interchange, passes through residential areas, establishments, and institutions located within Caloocan and Quezon City, and crosses into Quirino Highway before the transmission line ends at Balintawak Substation, after crossing F. Carlos St. Inside the said substation are steel pole 515 and new pole 516 (with steel pole 516 was later placed with insulators used on line 3 of San Jose–Balintawak transmission line on September 2020).

The transmission line originally had 504 steel poles (1–55, 58–98, 100–263, 266–496, 500–511, and 515), 11 lattice towers (56, 57, 99, 264, 265, 497–499, and 512–514), and 12 portal towers totaling to 527 structures when it was first commissioned in June 1994.

Before the Lahar-Affected Relocation and Hermosa-Balintawak Relocation projects in 2003 and 2011, respectively, it had:

• 32 steel poles (126-158; located at the western side of Jose Abad Santos Avenue (Olongapo–Gapan Road); retired except steel pole 127 which was used on a cut-in connection to Meralco Duhat Substation)
• 3 portal towers (located between steel poles 139 and 140, and 144 and 145; retired)
• 1 h-frame wood pole (used to replace steel pole 143 because it was washed out by lahars from Mount Pinatubo; retired)
• 84 steel poles and 2 lattice towers located along MacArthur Highway and Pulilan Regional Road, respectively (228–313; steel poles 228, 229, 231, 259, 260, 261, 266, 267, 271, 275, 276, 283, 301, and 302 and lattice towers 264 and 265 were reused. The other 70 steel poles (230, 232–258, 262, 263, 268–270, 272–274, 277–282, 284–300, and 303–313) located in this segment, however, were retired.)

As of 2019, the transmission line consists of:

• 484 steel poles (Hermosa–Duhat segment: 1–55, 58–98, 100–125, RHB-01–RHB-30, 159–254, 257–265, 268–289, 314–429, and 3 steel poles used on its cut-in connection to Meralco Duhat substation in Duhat, Bocaue, Bulacan; Duhat–Balintawak segment: 5 steel poles used on the line's cut-in connection to the said substation including original steel pole 127 along NLEx, 430–496, 500–511, 515, and 516)
• 13 lattice towers (Hermosa–Duhat segment: 56, 57, 99, 255, 256, 266, and 267; Duhat–Balintawak segment: 497–499, 512–514)
• 9 portal towers
• 1 concrete pole (58A)

Overall, it has 507 transmission structures, with the line's Hermosa–Duhat segment consists of 415 structures while Duhat–Balintawak has 92 structures.

By province, the line has 4 structures in Bataan (4 steel poles (1–4)), 271 in Pampanga (257 steel poles (5–55, 58–98, 100–125, RHB-01–RHB-30, 159–254, 257–265, 268–271), 7 lattice towers (56, 57, 99, 255, 256, 266, and 267), 6 portal towers, and 1 concrete pole (58A)), 181 in Bulacan (178 steel poles (272–289, 314–429, 8 steel poles used on the transmission line's cut-in connection to Duhat Substation, 430–465) and 3 portal towers), and 51 in Metro Manila (45 steel poles (466–496, 500–511, 515, 516) and 6 lattice towers (497–499, 512–514)).

To protect the transmission line structures from corrosion, several steel poles, lattice towers, and portal towers (including replacement poles and towers that were constructed by National Transmission Corporation (TransCo) and NGCP located on some portions of the line) are being painted with aluminum paint. Some of the structures (i.e. lattice towers 497–499 and 512–514) were painted before the painting of steel poles was started. Painting of the transmission line's steel poles began in 2015. As of the fourth quarter of 2019, the line has 369 structures that were painted with aluminum paint (357 steel poles (89–98, 100–125, RHB-1–RHB-30, 178–254, 257–265, 268–289, 314–496), 11 lattice towers (99, 255, 256, 266, 267, 497–499, 512–514), and 1 portal tower).

Steel pole RHB-03 (of anchor or flag design), one of the replacement poles used in the Lahar-Affected Transmission Line relocation project, along Jose Abad Santos Avenue, Bacolor, Pampanga. Replacement lattice towers of Hermosa–Malolos–San Jose and Mexico–Hermosa lines can be seen in the background.

TransCo relocated its Santa Barbara Bridge–Villa del Sol segment through the Lahar-Affected Transmission Line Relocation project, using 30 replacement steel poles. It was completed in April 2003.[3]

In 2007, 3 steel poles were relocated due to the construction of Dulalia Overpass using 2 existing steel poles (473 and 475) and 1 replacement steel pole (474). NAPOCOR-era steel pole 474 which is a suspension tower and has triangle tower design, however, was retired.

The cut-in connection to Meralco Duhat substation was constructed to avoid line overloading and maintain N-1 contingency. It was completed on November 16, 2009. This cut-in connection to the said substation divides the transmission line into two segments and because of this, the line is now referred to as Hermosa–Duhat from Hermosa Substation to Duhat Substation and Duhat–Balintawak from Duhat Substation to Balintawak Substation.

In 2010, 3 replacement and higher steel poles (381–383) were used due to the construction of Balagtas Interchange, with NAPOCOR-era steel poles 381 and 382 which are both anchor towers and have flag tower design were reused as part of Hermosa–San Jose line while pole 383 (of suspension tower or flag design) was retired.

Replacement steel poles 285–288 (with 285–287 are suspension towers while 288 is an anchor tower and all 4 mentioned poles have flag design), part of the relocated San Simon–Pulilan segment of the transmission line, along NLEx in Pulilan, Bulacan.

The Hermosa–Balintawak Transmission Line Relocation project involved the relocation of its San Simon–Pulilan segment along NLEx using 58 steel poles (45 replacement and 13 existing poles) and 4 lattice towers (2 replacement and 2 existing towers). Relocation works along the said transmission line segment started in the first quarter of 2010 with the construction and installation of 45 replacement steel poles (229–233, 237, 238, 241, 242, 244–246, 248–253, 257–265, 268–275, 277–280, 282, 283, 285–288) and 2 lattice towers (255 and 256) and the transmission project mentioned before was completed on March 25, 2011.[4][5][6] On June 2011, three months after the completion and energization of the relocated San Simon–Pulilan section of the transmission line, removal of 84 NAPOCOR-era steel poles (228–263, 266–313) and 2 lattice towers (264 and 265) as well as the retirement of 70 out of 84 steel poles (230, 232–258, 262, 263, 268–270, 272–274, 277–282, 284–300, 303–313) that were located along MacArthur Highway from San Simon, Pampanga to Caltex in Calumpit, Bulacan and Pulilan Regional Road from Calumpit to Pulilan Exit in Pulilan was completed.

Left: Steel poles 164–166 (of anchor or flag design) along Jose Abad Santos Avenue, San Fernando, Pampanga. The square asphalt marking at the middle of the road is the location where steel pole 167 was originally located before its relocation at the side of an avenue in 2011 using NAPOCOR-era steel pole 275 and also retiring pole 167 itself. Right: Steel pole 167 (using NAPOCOR-era steel pole 275 and of anchor or flag design) near Dolores Flyover in San Fernando, Pampanga. Originally located at the middle of Jose Abad Santos Avenue, the said pole was relocated at the edge of the road because it posed a safety hazard.

One steel pole that was located near Dolores Flyover was relocated at the edge of Jose Abad Santos Avenue while the relocation of the transmission line's San Simon–Pulilan section was ongoing using NAPOCOR-era steel pole 275 which was originally located along MacArthur Highway in Calumpit and now serves as the line's steel pole 167 since 2011, while pole 167 itself was retired.

In 2019, NGCP constructed new steel pole 516 located inside Balintawak substation.

Currently, the San Fernando segment of the line is undergoing relocation through the Relocation of Hermosa–Duhat Transmission Line project to alleviate heavy traffic along Jose Abad Santos Avenue due to the presence of its electric poles standing on the highway itself, and to pave the way for the expansion of some segments of the avenue, particularly at Barangay Dolores.[7][8] Construction of foundation of new steel poles was started in 2018. This is the third time where relocation works along the line's San Fernando section is made, after the Lahar-Affected Transmission Line Relocation project in 2003 and the relocation of steel pole 167 at the edge of Jose Abad Santos Avenue using NAPOCOR-era steel pole 275 in 2011.

The planned realignment of the transmission line's San Fernando segment along Jose Abad Santos Avenue was met with opposition from businessmen and residents. Fernandino Jasa stakeholders, a group composed of owners of different businesses and residents of Villa Barosa Subdivision, expressed their concerns over the potential risks and hazards on their health and properties if such relocation is implemented. One such risk is the probability of the lines being cut and swung towards buildings during natural calamities like earthquakes and typhoons, endangering human lives and properties. Levy Laus, chairman of the Laus Group of Companies, pointed out the negative impacts of the transmission line to the aesthetics of the city and the potential development of highrises and skyscrapers along the avenue. Several residents also took note of the lack of coordination between them and the NGCP. Laus suggested that steel poles be instead relocated in less-populated areas like open areas or paddy fields.[9]

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  Portal towers located between steel pole 98 and lattice tower 99. Nearby is the Mexico-Hermosa transmission line.
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  Steel pole 234 (of anchor or flag design) near Tulaoc Overpass in San Simon, Pampanga. Note that it uses NAPOCOR-era steel pole 228.
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  Steel poles 235–237 (with 235 and 236 are anchor towers and have flag design while 237 is suspension tower and has triangle design), located along NLEx, are visible from MacArthur Highway in San Simon, Pampanga. Note that poles 235 and 236 use NAPOCOR-era steel poles 229 and 231 while 237 serves as replacement steel pole.
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  Lattice tower 255 located between Pampanga River in Apalit. It is used as one of the replacement lattice towers (along with 256) due to the relocation of the line's San Simon–Pulilan segment in 2011.
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  Steel pole 424 near Ciudad de Victoria interchange. Originally had a triangle design from 1994 to 2019, it was changed to asymmetric due to the construction of the said interchange.
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  Steel poles 426–431 and original pole 127 along NLEx in Bocaue, Bulacan. Pole 426 is an anchor tower and has flag tower design while poles 427, 428, 430, and 431 are suspension towers and has triangle design. Original pole 127 and steel pole 429, however, are branch pylons and used to connect the transmission line to Meralco Duhat substation through its cut-in connection with the said substation.
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  Steel pole 474 near Dulalia Overpass in Valenzuela. Originally had a triangle design from 1994 to 2007, the said pole was changed to flag design when it was replaced by newer and higher ones due to the construction of an overpass mentioned before (and also retiring NAPOCOR-era steel pole 474).
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  Steel poles 493–495 (with 493 is suspension tower while 494 and 495 are anchor towers and all three mentioned poles have flag design) along NLEx and near Smart Connect Interchange in Valenzuela and lattice towers 497–498 (with incomplete tower designs, 497 itself is an anchor tower and 498 is a suspension tower) passing through residential areas within the said city.

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