Saturday, June 15, 2013

Guide to radars and defence equipment installed on HDB blocks and commercial buildings in Singapore

Sea sights: A unknown radar and EO mounted on the roof of HDB Block 14 Marine Terrace commands a panoramic view of the Singapore Strait, a major artery of world trade. The radar is thought to be the Elta EL/M 2226 Advanced Coastal Surveillance Radar (ACSR).

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In May 2013, a written reply to a question raised in the Singapore Parliament on "defence equipment installed on HDB blocks" got us curious about the type and number of such hardware atop public housing built by Singapore's Housing and Development Board (HDB).

The question and answer is reposted in its entirety below.

Ministry of Defence (MINDEF) website.
Posted: 13 May 2013, 2100 hours (GMT +8)
Written Reply by Minister for Defence Dr Ng Eng Hen to Parliamentary Question on Defence Equipment Installed on HDB Blocks

Assistant Professor Tan Kheng Boon Eugene: To ask the Minister for Defence
(a) whether defence equipment, such as radar, are installed on HDB blocks and, if so, what are the reasons for doing so;
(b) how are public health, safety and security concerns managed and mitigated; and
(c) whether these installations pose an added danger to HDB residents during times of military conflict.

Dr Ng Eng Hen: "There are less than a handful of defence equipment installed on HDB blocks as part of SAF's surveillance network to ensure Singapore's security. These were sited only after all other viable alternatives had been exhausted. These equipment pose no adverse effects on health of individuals as they keep well within international norms and standards required by local agencies. In fact, the measured levels are similar to base stations for mobile phones that have been set up by commercial telcos across the island.
These installations protect all Singaporeans as they serve to prevent attacks on Singapore."

Senang Diri's findings
About Asst Prof Eugene Tan's question:
We found that Asst Prof Eugene Tan's family lives in Marine Parade. This could have triggered the question from the Nominated Member of Parliament (NMP) on this somewhat arcane subject as hardware - which this blog believes to be "defence equipment" - was observed on a block of flats in Marine Parade.

His question on public health could have stemmed from worries over long-term health implications having his loved ones in the vicinity of "defence equipment" which appears turned on 24/7.

In the United States, for example, there have been concerns that overhead power lines may have led to a rise in childhood leukemia. Whether living nearby to "defence equipment" (such as radars) in Singapore would result in elevated cancer risks and other health complications would be areas of concern for the layperson.

About Defence Minister Dr Ng Eng Hen's reply:
The pointed questions on 1) public health, safety and security and 2) whether these installations pose a danger to civilians (HDB residents) during a war were only partially answered.

In the opinion of this blog, DM's reply did not address the question "whether these installations pose an added danger to HDB residents during times of military conflict". In simple language: Would the installations, presumably used by the Singapore Armed Forces (SAF), represent a legitimate target under the laws of armed conflict?

In addition, DM's reply that there are "less than a handful" of defence equipment installed on HDB blocks led to speculation over MINDEF/SAF's definition of what constitutes "less than a handful". We set the number at less than five HDB blocks.

The obvious question was where these blocks are located.

We found radars on HDB blocks in Marine Parade and in Woodlands.

* Both radars were installed on the roofs of 25-storey point block HDB flats. These were built before legislation made it compulsory for flats to have a household bomb shelter.

* Radars in Woodlands and Marine Parade are of different types. The one north keeps an eye on Malaysia while the one in Marine Parade scans coastal traffic towards Indonesia's Riau archipelago.

Radar at Block 215 Marsiling Lane, Woodlands - Elta EL/M 2226 ACSR short range radar?

The Woodlands radar has a commanding view of either side of the Causeway road and rail link which connects Singapore with Malaysia. It appears to be sited there to keep an eye on seaborne traffic in the Johor strait.

This apparatus on Block 215 Marsiling Lane is the northernmost radar site on the Singapore mainland.

We are not radar experts but the shape and form of the antenna appears to conform to that of the Israeli Elta EL/M 2226 short range gap-filler radar.

A close look at the infrastructure on the roof indicates that there may be an electro-optical (EO) ball mounted on one corner of the roof. The images you see above were captured from Johor.

Radar along Keppel Road

For the sake of completeness, the survey included commercial premises. This resulted in the addition of a building along Keppel Road to the findings. This radar is of a different type from the arrays seen in Woodlands and Marine Parade and appears to be connected with the control of shipping entering and leaving Singapore harbour.

Radar on HDB Block 14 Marine Terrace - Elta EL/M 2226 ACSR?

The radar on Block 14 Marine Terrace is fitted on the life machinery room of the block of flats, which was built in the 1970s on reclaimed land. The HDB point block has four units on each floor, each with a different facing linked by two lifts in a central lift shaft, for a total of 96 units.

The unknown type of radar comprises two dish arrays stacked one on top of the another. The shape and form of the radar antennae is thought to resemble the extended range variant of the Israeli Elta EL/M2226 Advanced Coastal Surveillance Radar (ACSR). The X-band device is said to be able to track 500 surface contacts simultaneously.

If this is the case, then this would confirm the emitter as "defence equipment" used by the SAF to build up its sea situation picture.

The orientation of surveillance is south-facing, towards Indonesia's Batam and Bintan islands. On the north-facing side, there appear to be baffles behind the radar which screen the emitter from TV and assorted aerials which crown the roof of Block 14.

Sweep rate was observed at around 60 revolutions per minute. At its perch 26-storeys above ground (including the lift machinery room), the radar horizon has an unobstructed view of all coastwise traffic in the Singapore Strait.

As with the arrangement at Marsiling Lane, there appears to be some sort of electro-optic device paired with this radar. This device is backed by the same sort of baffle which screens the device from the radar immmediately behind it.

Some views of the radar antenna are shown below for radar enthusiasts. Please compare and contrast the images with that of the Elta EL/M2226 ACSR.

Elta EL/M 2226 Advanced Coastal Surveillance Radar (ACSR)

Legitimate target?
The addition of "defence equipment" such as radars and EO on civilian buildings may make such property legitimate targets during a war should a belligerent want to knock out the SAF's eyes and ears.

It will be clear that hostile action taken to destroy, degrade or disable the radars will affect residentials not just in the host block, but those hunkered down in apartments in the immediate vicinity who are in the blast radius of ordnance dropped on the radars.

It will be interesting to know what sort of drawer plan MINDEF/SAF have drawn up for a Period of Tension which would ensure the safety and wellbeing of residents who live with a radar over their heads.

Should you know of any other HDB blocks with radars on their roofs, please contact me at


LiTTle_gH0sT said...

Great, by posting such detailed information you are inviting the whole world to know where exactly our defense radar is, what type of radar we use. Although i believe that's not all.


Anonymous said...

Totally agree with Little Ghost there...

You even put the exact address of the radar. If you are worried about the effects it posed during periods of conflict, all the more you shouldn't put this up for ALL public viewing.

Anonymous said...

Since it is a frequency-modulated continuous wave radar ((FMCW) it is good for tracking moving vehicles and boats and their speed. Therefore it is not an air defence radar and invites no enemy targeting. Also, as it its antennas do not rotate, there is little radiation sweeping the neighbourhood or causing radiomagnetic interference. X-band radars such as these are high precision ranging radars and operate above the frequencies of non-radar devices. OK, lah.

Anonymous said...

Greeeat... you trying to give potential terrorists and enemies of the state a one-up is it?

Anonymous said...

Little ghost and friends,

The straits times already published the address of the radar when residents raised concerns with their MP during the general election period.

No matter which agency operates the radar, it provides a battlespace picture and is a legitimate target. I am sure you will expect the RSAF to bomb a similar enemy radar. Don't be hypocritical.

And to Anon 9.54pm who said the radar does not rotate, the radar at woodlands does rotate.

You should also consider the cancer risk not just from the radar beam, but also from radiation from the RF emitter and from the high currents flowing up the block and enable the radar to detect ships all the way to the horizon.

Try this illustration: When our RSAF Super Pumas land on our RSN ships, the ships turn off their radars temporarily because they pose a health risk to the pilots and cause interference to the aircraft.

Anonymous said...

An FMCW radar is a low power radar. As it is continuous waves - plus a short range of a few tens of km, the average power is low - some 100 watts or so. The frequency modulation or FM part is for gauging the Doppler Shift for indication of velocity and whether the targets are incoming or outgoing. [Remember the Iranian Airbus shot down by the US Navy?] It is different from the naval fire control radar or surface tracking radar of ships. These are pulsed radar and certainly long range and powerful. Ships have 2 types of radar: one search and one for fire control. Same as in an airport. A long range (powerful) radar and a short range precision radar. They work in different frequency bands: S and X respectively. Note that there used to be some surface to air missiles placed on rooftops of high buildings after 911. They were there to ensure that the Shenton Way of skyscrapers would not fall victim to an intruding airliner. It would be shot down at least ten or more km away.

Anonymous said...

Anon 8:44pm: The Doppler shift is taken from the CW instead of the frequency modulation. The frequency modulation part is to increase the frequency for easier transmission to by using a higher frequency.

Anywayz, I believe that Eugene guy's family is a "new-kid" to Marine Parade. Those who have been staying there long enough will have attended meetings with those people who installed those rotating gadgets. And it is not something that was recent.

Is it a case of rich people making lotsa noise again?

The said...

Little ghost - do you seriously think that potential enemies do not already know the locations of our radars?

David Boey said...

It's on nights like this, when visibility is piss poor with the Pollutant Standards Index at 290 (!) that I'm glad we have that radar network and EOs to help watch our coastline.

To readers in Indonesia and Malaysia, hope you're all coping well.

Anonymous said...

Feel for the guys who are out there doing guard duty prowling.

Anonymous said...

You mentioned,
" The images you see above were captured from Johor."
That's interesting!

Anonymous said...

If the primary purpose of these radars is to monitor ship traffic, then perhaps they are under the control of police coast guard, and not SAF?

The haze of the past few days has shaken some of my confidence in SG's longterm survival - can an enemy blind us / weaken us simply by setting fires? (visibility was down to 100m in my neighbourhood) There was a financial news report saying the haze could cost SG 1-5% of its GDP, and if the haze situation recurs annually, foreign investors could lost confidence in investing here. Will you do a piece on maybe the military aspect of this topic?

David Boey said...

Hi Anon (above),
Re: Haze-related posts. Yes, I intend to post something tomorrow.

The wall of grey when the PSI hit 401 this afternoon was a memorable sight.

Take care everyone,


Anonymous said...

Why not Mindef install a radar at the back yard of Defence Minister Dr Ng and see what he says? Since its within that of a mobile phone transmitters. BTW there are cases of people overseas gotten blood cancers after prolong exposed to mobile phone radiations.

Does he get his facts correct? If he is correct, then we should see a radar in his garden very soon!

Anonymous said...

Now that we knew where your 'eyes' at dude.. ;>
peace no war///

Anonymous said...

We just used for our surveillance.LOL